I get the complaint with starfield since transferring stuff to your companions or ship is such a pain with their awful UI, but it's not even an issue in BG3.
99% of the time my party members have plenty of room to store all my shit, and in the rare occasion they don't it's a sign I have tons of shit to sell. On the even rarer occasion I run out of room in a situation where I can't easily leave, I can just send my extra crap to camp. Mind you, besides Shadowheart(Str 18) me and my party members all have base strength.
You can multi-select items and mark them all as wares at once, just only for one character at a time. I agree all wares should be pooled between characters though, or we should have the option at least.