Just like with shove, I can't count the number of times I've used Sleep on one hand, because 0 requires no counting. There are other reasons I would opt to not use Sleep over say Magic Missile, or Flaming Bolt. Why CC it if I can simply kill it instead? It achieves the same end, removing that mob from combat, with 0 risk of a party member, or another mob, breaking the CC. IF we want NPCs using the same rules as PCs, then some of this is to be expected, yes?
I'm not exactly sure what you're trying to say; what is the "this" in your last sentence? I do want NPCs to use the same rules, but in my mind that means neither of us should be able to wake allies up with a bonus action. Or sleep should be buffed to account for this ease of waking up.
For Sleep, the reason why you'd use it over an attack is because you *should* be able to
automatically sleep 3-4 low-level enemies, whereas damaging attacks/low-level spells typically only target one creature (and might not even kill it!). Up against 10 goblins, sleeping 3 or 4 of them is much more valuable than killing a single one, as it either removes 3 enemies from combat for 1 minute, or makes 3 goblins waste their attacks to wake up their allies.
However, in BG3, Sleep will probably only affect 1-2 creatures, and they can very easily be woken up via enemy bonus actions. So I agree that in BG3 it's almost always better to use any other ability, which is a problem.