Honestly, I think injuries have the most potential to derail him. Not your normal tennis-body, more like soccer. I worry about muscle pulls and tears. Nadal managed to avoid it in his career for the most part. I also wonder if he can maintain this tennis intensity (working and training harder than anyone) and the love of the game for a decade-stretch. It's very difficult. The mental game always needs tweaking, although he's been on point since the French Final.
He won't win them all. Nobody does. I think Rune and Sinner have the games to push him, but he is clearly a notch above them. Some others will step up and try to challenge. Good luck.
Alcaraz certainly has the look and is well on pace to be a double-digit major winner. There aren't many of those around. He is awesome to watch.