his ceiling is the floor
That made me laugh. He does seem to hit the floor in every game he plays.
To the OP's comparison with DWill, I have no clue what he is seeing.
DWill in earlier days could shoot, pass, handle, drive, hit 80+ % FT's, and could defend.
Rivers right now can't come off a pick, is not a natural passer, can't drive & finish with his left hand, drives right & ends upon the floor, 50-50 when he gets to the line, and is exposed every game on defense.
I don't see the comparison, even with eventual/natural improvement & growth.