Might consider calling them “players” instead. Basketball, football, hockey, chess, or e-sports players are all playing a game. Not all athletes are players and not all players are athletes.
Webster defines an athlete: “a person trained or skilled in exercises, sports, or games requiring physical strength, agility, or stamina.” IMO, e-athletics don't require any of the above. Mental stamina yes, but not physical. They don't use strength or agility. That's my line.