OK, so I learned a few things that I didn’t know before reading this article:
1. Osama bin Laden wanted to kill Obama but leave Biden unharmed because he knew that Biden was an incompetent boob who would put the US in crisis.
2. Biden had two brain aneurysms in the 80s.
3. Biden has a heart condition that can diminish brain function or cause a stroke.
Why didn’t Trump and the GOP use any of this in the campaign?
It wouldn't have mattered. Everyone was focused on the 24/7 BLM/Antifa riots. The media was stoking those fires by publicizing new police shootings every few weeks. And then all that Covid hysteria. The "Trump is Hitler" hysteria. The "Russian conspiracy" hysteria.
On top of all that, many conservatives had been deplatformed by 2020. Trump's supporters were no longer able to amplify favorable news stories on social media.
Any negative revelations about Biden would have been lost in all that noise.
Even so, Trump did win. But voter fraud did him in. So again, these revelations about Biden would not have helped.
BTW, anyone notice how all the BLM/Antifa riots have melted away. Police still shoot black thugs, I suppose. But now even BLM doesn't care. (Or at least, BLM's Deep State puppet masters don't care.)