There was a local contest where I am and his entry for that was his latest game which has multiplayer support over the net. He set up a server on a VPS for this. https://waitinggodot.in/games/legends-of-crumbs.html
Competition and one-upmanship to that level in kids has existed since the internet became widespread. The solution is to build something even better the next time you show something to that friend.
Just like sports, music, grades. Once the bar is raised, the top performers just keep getting better.
Have you played competitive sports in your life? The kids who practiced more, had more opportunities to practice, grew up around athletes in the home, etc. will also have that "I can do exactly what you did. That's easy!" attitude. That's normal.
If you get instantly discouraged by others making your hard work look easy, then you don't have enough drive.
My main barrier against this has been to talk with him regularly about this. Amplify the positives rather than warn about the negatives so that the first gets done more and the latter gets atrophied.
"Everyone else is doing this obviously bad thing to their children, so I might as well do it to my child too!"
Brain rot is not a serious term… anything can become a problem if it’s done too much and often compared to ‘other things’
He's been publishing his work at https://waitinggodot.in/
My younger one has been creating little things on a microbit using the block based environment online. He's enjoying it too.