billd91
Not your screen monkey (he/him) 🇺🇦🇵🇸🏳️⚧️
I'm with Oofta - combat in 5e generally has fewer rounds rather than more, but I could see it potentially turning into a slog if one or both sides are very difficult to hit, do insignificant damage on a hit, or both.
I've had this happen once or twice, but it's always been with 3rd party monsters. Some of them follow some very different build principles that you end up having to decode in the course of a fight to beat them.