It’s an absolutely ridiculous basis to make a claim.
Hans Niemann was almost 17 years old when the pandemic started. When he turned 15 (June 2018) his rating was 2313, almost 200 points (an immense gulf at that level) below the minimum to become a grandmaster.
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You even managed a double-entendre in 2 completely different realms. Well done.
I find this true for any semi-competitive endeavor that doesn't also have intrinsic extra benefits. You're going to hit the people who want it more than you and are willing to put in the practice time, and they're going to beat you.
Consequently, any competitive thing I do has to also have an extra dimension to it. A competitive sport is generally fine since I'm getting in better shape. I'm happy to do stuff like darts or bowling if it has a high social aspect to it. As long as I can be slightly above average and that's good enough and there is some extra benefit, I'm down with it.
Chess, sadly, generally fulfills none of those criteria.
This is confusing correlation and causation.
One thing that people don't realize is the sheer amount of money required to become a "GM". You have to get a certain number of "norms" from FIDE and the requirements list is a PITA: https://chessgoals.com/how-to-get-a-grandmaster-norm/
If you don't have a lot of money and a lot of free time to go to a lot of chess tournaments around the world, you are not getting a "GM" title in this day and age. This favors children (few time constraints) with rich parents (lots of coaching along with the ability to travel).
The problem is that if you aren't a "chess prodigy" by 15 it generally isn't worth continuing to pursue--what does sinking the resources into being a "GM" get you at the end? If you're one of the "Chess Gods", you have entry into the tournaments anyway, and, if you're not, it doesn't really matter.