A thing nobody pointed out is what happens when you need to have the whole party jump. First one jumps, ok, second one jumps and first one goes nearby even if there is fire or vines; you move them away, have the third jump and first two come near, crossing again the vines. Going out from Zorru house in groove was a real pain, not to speak of the window of the burning house where you find the wife of the guy you saved in the inn.
Someone mentioned DAO, but i dont remember having problems moving the party there, or at least having that many problems.
As a bonus consideration: this system Larian uses makes managing a four-members party way more cumbersome than moving around a full party of six men in a game like Pathfinder: Kingmaker.
Imagine if Larian listened to the (VERY popular) request to increase party size to six without addressing these controls first. A request I'm all in favor of, I may add. It would turn minute party control from just bad to an unmitigated disaster.
If people want a six-members party (as it seems, given that the discussion about it is the most popular thread on this subforum) addressing this issue is basically a pre-requirement.