Counter-argument: the possibility to group "UP TO six people" doesn't force anyone to reach the number of six.
The old Baldur's Gate/Icewind Dale games were often played even with solo characters or parties of 2/4 members by dedicated powerplayers. That was achieved simply allowing small parties to level up faster.
Bogus reasoning here.

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