Chess has been played for centuries, people have taken it so seriously that they spent their lives studying it, hundreds and hundreds of books have been written about chess, the world's biggest television sensation of 2020 was about chess, it's a worldwide phenomenon, there are several thriving websites such as this dedicated to chess. What do you mean it's not popular?
If you mean "why isn't it played in 75,000 seat stadiums and broadcast on nationwide TV?", sober up. No board game has that kind of spectator appeal. Chess is a difficult game to master, and most people who try their hand at it give up quickly. So there are only relative few of us that participate in and follow chess. Still, that "relative few" is millions worldwide.
This was not true when I was a kid. I couldn't find an opponent other than my dad untilI I could drive myself to a chess tournament. I think the popularity now is pretty good by comparison!
I guess every sport wants to be more popular, MMA fans probably want to be more popular but I'm not watching people mutilate each other.