He needs to work on strength and toughness in a big way, but there's real upside. He gets in the lane and gets over the rim quite easily, and he's really just a kid. The thing that already stands out about him to me is his court awareness, IQ and decision making. He makes reads and makes the right play at game speed. The ball doesn't stop. Then he's got the body control to make a play and get his defender out of position. He has some of the same 'intangibles' that Gordon Hayward has, and that gives him a lot to build on. He also has the ability to pull up from 10 feet and hit a running floater, which is a skill move for a guy that size.
Yeah, he needs to stop throwing the same fake-then-drive move, which will stop working when teams scout him, but he's got a nice face-up game developing in the mold of a Carlos Boozer. Plus, compared to Boozer, Lyles has more length, better body control, and he plays defense. He could become a 20/10 player or something awfully close to it within a few years, if he gets featured in the offense.
He's not the first versatile PF with size though. Locke is exaggerating a bit there. I mean, KG, Bosh and now Blake Griffin all have pretty complete games with some shooting range.