Video games like chess do not really require physical fitness. Yes. I know professional chess players exercise to improve their thinking and general stamina. But it is not required at all in general. Physical fitness and development of some physical abilities is what separates sports from non sports. And not every physical activity is a sport of course.
Chess doesn't have to be a sport for people to enjoy it. It makes no difference at all.
There are many arguments for why chess is a sport, including:
The International Olympic Comittee, quite possibly the most 'official' sports authority in the world, considers it so.
It bears almost all the characteristics of games that are definitely sports, such as basketball, baseball etc. Physicality is the ONLY thing missing.
And even that idea can be challenged, becuase tournament chess clearly requieres a lot of stamina.
Meanwhile, the ONLY argument I've ever heard from the naysayers of the idea that chess is a sport is "But it's not physical (enough)!"
The thing that neither side realizes is that THERE IS MORE THAN ONE DEFINITION OF THE WORD 'SPORT'. There is no 'official' or 'objective' definition. Many defintions include chess, while others do not. None of the definitions are 'more correct' than the others.
The two different sides don't really disagree on anything chess related, only on the definition of a word. So, I present to you, the objective truth on the matter: it depends on what definition of 'sport' you go by, and they're all equally correct. By the definition I go by, chess is a sport. But ultimately, the debate doesn't even matter. Because there IS NO ANSWER. Neither side is 'right'. And a debate of the merits of different definitions would be absurd and almost impossible to reasonably conduct.
Argument over. Forever.