Pong is great. The biggest problem is it is a two player game and most people play online now. Single player is possible but with AI it is not the same and without AI you get BreakOut/Arkanoid etc...
Another problem is the lack of paddle controllers. Pong sucks with a joystick. No ifs ands or buts about it. Analog sticks are slightly better but the twitchy ones we have these days are not up to the task, the 5200 was the only analog stick that could almost pull it off.
Many people think that if you want simulated tennis/ping pong you should just render full environments and play the proper game... but Pong was something else. It wasn't a true simulation it was abstract to the point of becoming its own thing.
The other day I introduced my 18 year old nephew to paddle controllers and pong, video Olympics, Circus Atari, Warlords, Kaboom... we had a blast, for hours. Once he bought in to it he didn't mind the primitive graphics and saw the beauty of a proper paddle controller for these games despite having no idea what it was when I handed it to him. So these games still have appeal and value. It's a matter of presentation and control.
Pong translates poorly to phones and other small screens, your finger covers too much of the screen and forget two players. Playing online dies due to lag.
Pong however plays beautifully on a Microsoft Surface or other mid to large sized tablet. They are big enough to play two players and also big enough to still see the paddle under your finger. I have a version on my tablets at all times, just in case. I have had many takers over the years and they all enjoyed it.
That is also another problem with Pong. It's so simple that it can be used to teach beginning game programming and few are going to pay for a game that could easily be knocked out in a few lines of code. Heck even BASIC for Atari 3600 had a pong game as a lesson and that was input using the keyboard controllers in just a few minutes.
Pong tournaments though... it marketed right or done trivia night style at bars could find a niche following.