Ilia Topuria says he chooses not to use his wrestling because he wants to entertain the fans:
"If I wanted, of course I can take [Gaethje] down and do whatever I want to him. But I really want to give the fans a show.
With Max [Holloway] also, I could've taken him down, control him on the ground and submit him, but it wouldn't be as exciting as it was.
That's the same thing I'm planning to do with Justin, it's gonna be a pure striking fight. At least from my side."
(via @vicblends)