Stats on 21st Birthday (in order of PEP):
Nadal (96): 22 titles, 9 Masters, 3 GS, best rank #2
Alcaraz (67): 13 titles,5 Masters, 2 GS, best rank #1
Djokovic (49): 10 titles, 4 Masters, 1 GS, best rank #3
Zverev (19): 7 titles, 2 Masters, no Slam QF+, best rank #3
Rune (17): 4 titles, 1 Masters, 3 Slam QFs, best rank #4
Sinner (13): 6 titles, 3 GS QFs, best rank #9
Federer (11): 3 titles, 2 Slam QF, best rank #8
Tsitsipas (9): 3 titles, 1 Slam SF, best rank #15
Murray (8): 5 titles, no Slam QF+, best rank #8
The above is just a way of pointing out that Rune is sort of typical of a young player with great potential, at the point he's at age-wise. He's been solidly better than Federer, Murray and Tsitsipas, a bit better than Sinner. Close to Zverev (not that that's a good thing).