Even in Original Sin 2 you probably had on average 3-4 ways to solve any given problem. Your playthroughs will actually become different, since you don't have a Wizard at hand to dispel a magical barrier every time, but have to find another way around.
I think D:OS2 is a horrible example, as armor system and lack of RNG for stuns greatly simplified the gameplay, at least for me. Essencially every character specializes in physical or magical damage - once you burn through armor you can stun lock the enemy with whatever stunlocking skill you have. The goal is to make more DPS then your enemy aka. burn through their armor before they burn through yours. Half-team dedicated to physical damage, half to magic damage. Some utility spells like healing/armor up/positioning if particular development path supports it. That's it. I attempted three playthroughs (one completed) and no the game played very much the same. That game got incredibly repetitive after just couple hours. I don't think that game was every designed around party play - more around 4 coop players being able to do well without cooperation of their partners. That is also where Larian is taking BG3, I think. I don't think their additions are there to expand tactical possibilities, but for individual classes to be less reliant on support from others.
