The snap was pretty much the apocalypse though. Planes falling out of the sky, no more electricity, no more internet. For a while at least. That's pretty much what I'm envisioning, maybe a year or two of post-apocalyptic living. Even after the five years, the world still looks like it ended in Endgame. I don't think its farfetched to see the remaining 50% clustering together in less affected areas, hence the immigration. I'd imagine there would be a lot of people travelling all over the world in general, trying to find out what happened to their loved ones and reuniting with them, maybe settling down somewhere new. You could bet your ass that I wouldn't be staying in my shithole of a country after the Snap, it would get all Mad Max in an instant.
You're right that immediately after the Snap, a lot of things would start going wrong in the way you describe. However, you're describing things on a global level. Everything is going to go bad, everywhere. Maybe worse in some places than others (e.g. if you look at modern plane routes, Europe and Asia are heavily covered compared to Africa, so they'd have more planes falling), but if you're referencing Mad Max, Mad Max is the whole world going bad. It's pointless to try and immigrate because you're exchanging one shitty area for another shitty area.
If we're talking about stuff like a lack of electricity, or vehicle destruction, yes, some countries would be more affected than others - losing electricity doesn't matter if you never had electricity to begin with (see many regions of sub-Saharan Africa). So in theory, some regions of the world might want workers to help them out. However, those same regions would have had a 50% loss in population as well. Sad reality is is that this would likely open up opportunities for the survivours, such as being able to haggle for better wages. There's historical precedent for this (see the Black Death), and real-world precedent for this - want to know why sweatshops can pay Bangladeshis so little, even if it's still better pay than what they'd get in other jobs? Because if you don't want to work in a sweatshop, there's plenty of people who can take your place. Don't think I'm arguing that wages shouldn't be higher, but if your choice is immigrating to a wealthier country, or taking stock of a sudden surge in opportunities in your own country, I'm not sure if that would be such a clear-cut choice.
Of course, this is debating the semantics of a fictional setting, but of what the fictional setting itself has provided, society was functioning normally in Endgame and in Far From Home. Even if both reference the effects of the Blip, society itself is functioning the same way it was originally. And even in the show itself (based on what I've seen), society clearly hasn't collapsed a year on from the Blip. Sam may have difficulty getting a bank loan because so many people are similarly applying for loans, but things seem normal everywhere.
I'm pretty sure that was just a figure of speech. What are borders worth when the world has just ended? The government was in shambles, who would be controlling the entry of refugees and immigrants? People were just freely moving between countries for five years. That's a lot of time to get used to something enough for you to be angry that's its being taken away.
Well, from an in-universe perspective, we already know that governments didn't collapse. Going by Endgame, governments were able to quickly deduce what had happened (Black Widow says towards the start of the film that the world's governments are conducting a census, and have deduced that about 50% of the world's population would have been lost). Even then, if a government loses 50% members of its staff, that sucks, but you've got 50% fewer people to actually govern. Similarly, if we're talking about border control, you may lose 50% of your border guards, but the no. of people you're trying to keep out has dropped by 50% as well.
If some areas of the world were worse affected than others, then yes, there'd be migrant flows of some kind, but so far, there's been nothing to suggest that.
There was no hold up, which I think was the point. These people made new lives for themselves in the five years and now the governments of the world just want them gone. You just spent five years making a place your own, only to be told to fuck off so some rando can enjoy everything you've worked to rebuild.
There's actually a way the show could have handled this, and a precedent was set in Far From Home, where it's established that the Blip led to an upsurge in homelessness and other similar issues. As I've mentioned earlier in this thread, the Blip would logically lead to issues within countries, but it doesn't make sense that it would lead to issues between countries as far as refugee flows go.
Thing is, there's a morally ambiguous case here. Say the Blip occurred, and I was blipped out. In the five years, someone moves into my house. I then blip back, and find these randos in what was "my" house five years ago, but is now theirs. Who has ownership of the dwelling? You can make a moral case for either side. However, at least so far, the show hasn't done that. If people move in from one country to another to make up for a fall in population, and five years later that population comes back, who has right of residence? Again, you could make an argument for either side, but the show hasn't engaged in that argument. If anything, it takes the opposite approach that Far From Home did. Which is fine, different people can stamp different takes on a shared universe, but I find FFH a much more realistic take (if anything about the Blip could be called realistic). FFH highlights stuff like losing one's home and family. FWS tries to show a refugee crisis, without actually showing us much of it, or explaining much of anything.
Also, this is arguably beside the point, but if we assume the Latvia of the MCU is the same as the Latvia of the real-world, I'm not sure that's the best example to use. Latvia's population today is in steep decline, so if anything, it would be more likely to welcome migrants than cast them out at the drop of a hat. Or, back to my EU comment, travel between the EU is very easy. Travelling into the EU is another matter (see the Mediteranean for instance), but all the refugees we see seem to be European in ancestry.
I agree that the show didn't do enough to highlight or explain the post Snap and Blip world, but I don't get why you see this immigration thing as so illogical.
Again, basically because the 50% drop would presumably be universal, and when similar population crashes have occurred, it hasn't led to mass exoduses. The Black Plague wiped out 60% of Europe's population for instance, it didn't lead to a resetting of borders, and exoduses occurred within countries rather than between countries. Similarly, if you look at the Americas, 90% of the Amerindian population crashed due to disease, but that in of itself wasn't the reason for loss of land. The Trail of Tears didn't occur because of a population crash for instance, it came because of a land grab. The population crashes allowed displacement from land, it wasn't the reason in of itself.
Also, even from an in-universe perspective, the idea of a refugee crisis doesn't really sync with Endgame or Far From Home. In Endgame, there's no mention of anything that FWS describes in terms of people moving, or borders moving. In FFH, Peter and co. can travel Europe without issue, and there's no evidence of any displaced population. So no matter how you look at FWS, from an in-universe or out-universe perspective, its worldbuilding comes up short.
