Haven't heard of 3 of those guys (Johnston, Montana, and Rose – perhaps they are darts or snooker players?),
but I'm willing to believe you.
Yeah, everyone is entitled to their own criteria.
Etymologically, though, for something to be considered a "sport", it doesn’t necessarily need to involve
physical exertion. The root of the word is
pastime, diversion from work – which is precisely why
driving to work is
not a sport, even though it requires some physical exertion/skill.
The boundaries are certainly blurry. Major chess tournaments have always been covered on
sports pages of traditional newspapers, suggesting chess
is a sport. Isn't Magnus Carlsen a GOAT candidate just like Connor McDavid is? He certainly is. And anyone believing you can neglect your physical fitness and still be an outstanding chess player, is deluding themselves.