Biden's mental deterioration is well documented and noticable, and the attempt by the media to hide it were also noticed by the population.
Biden hired a rogue's gallery of freaks like his nuclear advisor who kept stealing women's clothes at airports and still wasn't fired until basically biden had to.
The green new deal landed like a greasy turd into our economy. While not all of inflation was caused by Biden necessarily, his antifossil fuel stuff and opposition to pipelines added to inflation. He may not have been 100% responsible, but his policies certainly didn't help matters.
He completely and totally fumbled the Afghanistan withdrawal. August of 2021 was when his approval went underwater for the first time actually. Many people saw it as outright shameful.
Biden has run a campaign of anti-FOS initiatives, either working with Big Tech to suppress dissent or otherwise stifle freedom of speech.
Plus the usual stuff about Democrats overregulating and expanding government too much, poor border control/immigration policy but that's normal.
Anyway, that's how I see it. Did I miss anything?
Edit: one more: Harris just was an unlikable candidate. My wife mentioned she couldn't find a single person who actually liked her as a person. Very phony.