TON is making it big because it already has a very large audience.
Releasing the TON network attracted many users since it was launched by Telegram or their native app itself.
There was no trust issue in this case and hence it got massive audience welcoming the new chain.
On top of that the mini apps were something unique which we haven't seen yet and so it's a trend these days.
But trends fade away and so will the mini apps and if TON doesn't get something new then it will go down just as other coins.