I don’t know how fascism could possibly just ‘go away’ on its own.
Fascism kinda requires a single, “strong man” leader. The Achilles heal of all “dear leader” movements (autocracies, monarchies, etc.) is that the succession plan is garbage. People in these movements really get invested in “the guy” at the center of them, and it’s difficult for anyone else to scratch that same itch for them (e.g. Desantis).
If you run the clock out on Trump (i.e. he fucking dies of a filet of fish overdose), I suspect his supporters will go in the can right along with him.
The demographics are also changing and not to get all “demographics are destiny” on it, but if we somehow miraculously manage to stave off Republicans at the ballot box for a few more election cycles they may be forced to reform themselves in order to be relevant again…if it doesn’t spiral into out-and-out violence at which point politics are kind of irrelevant.