"Maybe this, maybe that. We could do X rather than Y" and so on.

Do we even realize that every suggested compromise so far boils down to making a terrible system somewhat less obscene to use, without any genuine hope to make it actually good?
Every time a partial modification that keeps the chain system around is suggested, it boils down to being a a proverbial case of trying to put lipstick on a pig.

Yeah, a quick keybind ot chain/unchain everyone on a button press WOULD make things better, and it was suggested since the beginning of this very thread even by myself. But when you think about it, its only function would be insisting to salvage a garbage control scheme.
It would be far better to approach this from the exact opposite position: what about giving us a decent control scheme that makes sense, to begin with, and THEN include an "everyone autofollow!" function as a toggle for people with dysfunctional hands who really, REALLY want to control only their MC.

Party control in Baldur's Gate 3 is a complete mess that begs to be addressed. SAY NO TO THE TOILET CHAIN