Dembele is a good player but it is true I don't understand the hype. Parker is a limited player, that much is clear. Dembele is also a limited player.
The things you mention as negatives about Dembele Parker is even worse at. Parker can't shoot for toffee, never picks out the easy forward passes, can't even do the easy sideways passes without slowing things down with a few touches first and unlike Dembele can't run past an opponent (unless it's to run INTO another player).