His defense is okay, good even, but PG defense doesnt add much to the game or team. His issue is that dude has a completely non existent offensive game.
Dude might not be a PG in a few years.
he's still growing and has a chance to be 6'7(according to doctors who measured him who also found out he grew an inch during the season) with his length and with experience he'll probably be guarding whatever teams best perimeter offensive weapon.
the league IS a pick and roll game and he's great at defending that. he just needs more time and to fill out.
he's 19 from another country and never done strength training dammit

he'll be younger than most of the upcoming draft

Most of his potential is based on him developing offensively to be honest.