Control spells are good throughout the game. Later in the game, your casters can have spell DC => ~20. Enemies will need something like Legendary Resistances to effectively resist.
A good case is Trickery Cleric Shadowheart.
As long as you don't resec, Shadowheart is able to effectively "command" some of the toughest enemies in the game.
Examples:
. Act 0 Zhalk (big boss at the start of the game)
. Act 2 Biggest Boss
. Act 3 All (but one) Steel Watchers
At the climax of Shadowheart's quest line, if she is NOT respec'ed, she can effectively disarm/disable the huge army she may have to fight. She can also summon an ally who has an extremely potent (small radius, though) control spell.
I love Shadowheart.
I also love Shadowheart, in several ways. But why should she disable/disarm people? Why not nuke the wet crowd with her giant aoe spells she has as Thunder Cleric? It's over much faster and more reliably, mostly.
This is just a showcase of "control" spells.
If you turn Shadowheart into a follower of the thunder god in order to eventually have her deal out a guaranteed minimum amount of 80x2 = 160 damage either on the party's 1st turn or by her own 2nd turn, what's left for you to enjoy most of those well crafted battles in Act 3?
On a side note, the more burst damage (from abilities not from items like barrels) you do, the more frequent long rests you have to take, which breaks immersion. Every rest is a break. Also, killing a large group in Act 3 with burst damage (again not from items) most likely requires level 11-12.
On the other hand, throughout Act 1 to 3, once you have disabled/disarmed a few key opponents, you are almost guaranteed a victory with no sweat. You wouldn't have to take a rest (break!) before & after every fight. You would be able to explore many places without a single break. This would feel nice and natural (in terms of roleplay), or not?
