It's not that I *don't* use them, but I find them.... A little underwhelming.
First off is meta-gaming. If I have a Sorcerer and I get to pick spells, I know that 90% of the second act is Undead, so I'm not picking Hold Person and so on.
Then, through items found throughout the game, there is nothing that really that boosts it. The game really wants you to do damage with every build. 'When doing blue damage, add the green debuff, when adding a green debuff add pink damage etc.
Then, I don't like 5E's over-reliance on concentration. I get it when you're holding up a giant wall of fire, say. But....
'Okay, so I haste myself, and now I have another action, so I use telekinesis to... Ah, dangit.'
That doesn't work for me.
Now, to make battles harder for the upper difficulties, Larian scripted the AI to always prioritize your party members that concentrate on things, but at the same time they'll refrain from attacking those that they can't hit properly. If I use my concentration to hold a few enemies, that means all of his mates kill that squishy mage. So, instead, I use my concentration to buff myself with - and then I go in 'Ogre kill everyone around' mode.
