Yes, I think combat is a lot of fun in D&D.
Now, I have played in campaigns where combat is not fun, so in my campaign I make sure not to make the mistakes I have seen of other DMs.
Firsty, in Theatre of Mind (my preferred way to play). Distances are crucially important. Distances are the biggest driver of decision making in combat in my opinion, and decision making is the root of what makes combat fun.
Although it takes a bit more effort on the DMs part during Theatre of Mind, it is crucial for you to be able to answer your players with exact measurements to inform their decisions. "The Orcs are 65ft away, there are large rocks slightly to your left that you could take cover behind, between you and the Orcs, 25ft away. There's a band of goblins to the East emerging out of the forest 120ft away. The wounded paladin is 20ft behind you. What do you do?"
Secondly, every combat needs a unique hook. You wouldn't present the same puzzle to players multiple times, nor should you present the exact same combat. There are infinite ways to do this, you fought 3 orcs last time amidst some ruins. This time you are fighting 3 orcs on a bridge with a perilous drop either side. Or this time the 3 Orcs have brought some wolves with them, or goblin archers, or it's at night time, or they are being sneaky instead of charging you in the open (being "kunnin' yet brutal").
I take pride in my combat encounters and I can see my players really enjoy them. At the same time, once we've had a particularly lengthy combat, I try to get them exploring and socializing afterwards to help maintain pacing. People can get fed up of pizza and ice-cream if its the only thing they eat.