Definitely not writing him off, I just think he's got a
tendoncy towards fragility (bad joke).
Who knows, maybe
@Fiero425 is right and contemporary players are going to fall off earlier due to the intensity of their play. I personally think it will be somewhat ameliorated by improved medical technology etc, but maybe we'll see more modest schedules relative to years past. I mean, we already saw a decline in matches played from the 70s on. In fact:
Open Era record for matches played: 147 (Guillermo Vilas, 1977)
Last 110 match season: Ivan Lendl, 1982 (115 matches)
Last 100-match season: Rainer Schuettler, 2003 (101)
Last 90-match season: David Ferrer, 2012 (91)
Zverev played 88 matches in 2024, which was the most since Novak played 88 in 2015.