They lost because of Biden.
No, not because Biden was old, or bumbling etc etc etc.
It was because Biden slow walked the insurrection and the stealing of top secret documents prosecutions (plus other illegal shit, but I'll stick with the big easily winnable ones here). What he should've done on day one was go hard on prosecuting Fatboy McKiddieFiddler, and taking out the corrupt/owned judges etc.
Instead Biden waited and waited, and tried to do it all in secret. And by the time it had got any traction it was time to do the elections again.