Makes me wonder if the notorious difficulty and aggression of ER's bosses was intentional in that FROM wanted to encourage summoning and build a community of cooperators instead of the ones of elitists its been known for, i.e.: make it so hard, players will literally NEED each other. Overly optimistic ideal, I know, but better than assuming FROM are just a bunch of sadists.
You know I'm not sure. With ER it's hard to say, because while it plays a lot like a Souls game it's NOT a Souls game. So understanding the approach Miyazaki wanted to take would likely require an interview where he spells it out for us.
My guess is that because of the open world nature, From added help systems like spirits in order to counter balance the difficulty of some fights. Because From doesn't like to give players direction and everything is vague on purpose, that means that they had to figure that players might end up anywhere at any given time. And if there was nothing the player could do except get fucking smashed at every corner it likely would have broken the experience. So the stakes of Marika, the summons, and possibly even the powerful weapon arts and spells, were scattered around so that the player was bound to find SOMETHING, and thus use it to get through the bosses in the game.
At the same time, the made bosses the hardest they've ever been in a From game to the point where I personally think the difficulty without extra game tools is unfair. There are many videos about this by Souls-veterans, where attacks and patterns and agression of these bosses have been looked at and deemed pretty unfair by Souls-Pros. However they still beat them, beating something unfair doesn't mean it wasn't unfair.
I hope for the next game they take a step back and look at the previous idea of tough but fair. Look at it this way you beat Bloodborne and it was hard as fuck, if the next game is about the same difficulty as Bloodborne you are still going to find it pretty though even if you might beat it a bit easier than Bloodborne. The beauty of the Souls formula, imo, is that the combat to a new player is brutally hard but it's learnable and as the player you can "get gud". There is an amazing joy in finally being "gud" and being able to carry it onto the next game, or even NG+ runs. That skill also can lead people to doing challenges like Level 1 runs, or bow-only, or whatever the fuck. But that stuff is only mostly possible because the game's all stay true to "Tough but fair".
While challenge runs still happen in ER, I still feel that ER has mostly crossed that line of what is "fair" for most people, leave the potential for those crazy runs only in the hands of Pro players.