It's really not that much later. You can find hirelings and the respec guy very early in the context of the massive playtime the game offers. Also you can legit do just fine with 2 fighters and especially 2 clerics, cause their weapon choice and subclass change how they play a lot. Like maybe one of the fighters can be more tanky with a mace and shield and the other can go for high dps with a greatsword or can be a ragned shooter with their archery proficiency, and clerics can kinda do anything, they can tank they can do damage they can heal they can buff, choice is yours based on their domain, stuff like that.And the operative word there is "later." I don't want to respec later, I want to start the game with a party I created. Even if it is for comedy purposes like I did with one run through ID2 with 4 1st level halflings, an elven ranger and a dwarf fighter.
Baldur's Gate has always been more story-driven than Icewind Dale. And that just naturally means less roleplaying potential. I'm not making MY character, I'm filling in the blanks on THEIR protagonist. I knew that going in, and I'll eventually probably have a great time with Baldur's Gate. But I'd have enjoyed it more if say... you could create 6 characters, that you find in the pods in the beginning. Or if their story is so central to the experience, at least let me choose what class each character is when you first meet them, and not after you've played the first several hours of the game and get to the town where the barber is that can change someone's entire backstory for a few gold.
Changing the class of the origins isn't available early because their class is relevant in their actual stories, it's inextricable. Like the whole plot with the Cleric is her being faithful to her god, she can't quite play that off well if you shift her faith to a different one, it'd be incoherent and that would bother way more people.