I've generally felt like 5e just generally lacks decisiveness in its combat. It's true that sometimes characters have more options (though I think that it's definitely a step down from 4e in that sense), but typically my experience is that combat drags out long enough that people start reusing their attack options and things slow down.

I also think that 5e just has some issues with DM resources and combat; it's simple to run in theory, but in practice I've found that it feels a lot more difficult than it should as a GM, and as a player I very rarely walk away from 5e thinking "Oh yes, that was a great combat where everyone was able to contribute."

Half of this comes down to the fact that d20 is just a little swingy, and sometimes you just don't have dice luck. When I play Degenesis, it feels like the only reason a character doesn't contribute in combat is because the fight ended too soon (or they got murdered in the first round, which happens from time to time).

I think there's really two issues here: the first is that D&D relies on players missing a lot to determine how good they are because they don't really have any damage scaling based on competence and the d20 system doesn't have a rule for doing so. When the damage of a hit fluctuates a lot, you can let players hit all the time.

The second is that D&D just flows miserably unless you're doing interesting things every turn.

5e's combat is almost all about hit point loss and the occasional status effect, where 4e had other options with movement and state changes being something that was as natural as pie. Because hit points scale linearly at a higher multiplier than damage does, you wind up with combat basically being a progress bar.