While I generally like, to love, most of these groups, it could be argued that without certain members, the group just wouldn't work or gel right.
To me, BTS would be A TOTALLY different group without the Maknaes.
Twice wouldn't function without Jihyo and Nayeon.
Blackpink would be dead without Jennie and Lisa.
Red Velvet would be sluggish without Seulgi and Wendy.
There would be no Big Bang without G Dragon and TOP.
Although there are a few groups that could still hold their own without certain key members like EXO and Girls Generation, most likely NCT.