Yeah, they massively overdid the wave spam bit. It would be okay in some scenarios where it makes sense (as in you attack a camp/base and they get reinforcements after a bit). But it also didn't make sense in other situations (like fighting in an old ruin and unintelligent beings like animals/undead/constructs join).

And due to those waves you rather conserved your resources when there were only 2-3 enemies left, cause another wave might come and you would be fucked without those cooldowns/resources.