I think part of it could be stability. A lot of the better pro athletes in traditional sports have been playing their whole lives (in basketball most people start in elementary school and play through high school and at least some college), and in europe some play professionally at a young age. They do also have a pretty long off season, which allows their body to recover, and some do complain of fatigue, especially teams that make deep playoff runs in consecutive years. In traditional sports, due to media rights deals and other sponsorships, athletes are paid millions and sometimes do not even play. However, in esports, while some players have been playing for a long time, they don't know when the money will run out, and what the format will be next year, let alone the meta. Their job is anything but guaranteed. They could be let go due to something outside of their control, or the money could just evaporate into thin air as we have seen recently.
You aren't really taking into consideration the amount that players in esports actually play the game outside of official matches. Sure, teams are in front of the cameras for anywhere from 40 to 110 hours a year, but they are also practicing (likely) at least 6 hours a day in and out of the server, and also play the game/stream outside of practice. All traditional sport athletes practice as well, but they also have recovery time that they can spend without having to physically play. Esports athletes, I feel use more of their non-practice time in the server playing and reviewing during the season.
Additionally, the staff for a lot of traditional sports are extensive, with mental health specialists, coaches for just about everything, and coaches do their best to allow the players to keep succeeding, for example, Steve Kerr would allow Steph Curry to play golf during the season.