I personally hold that Biden won. Our election system is far too decentralized to allowed for large-scale, coordinated election interference to be viable while also being covert.
I also believe that there was likely an uptick in rule-bending across the board. This was in no way a 'normal election', given the mass-adoption of mail-in voting, and heightened polarization of our political environment.
Unfortunately, the US has shown a remarkable lack of historical introspection with respect to election integrity, so it's impossible to tell with any certainty whether this is truly the case since it's I believe it's safe to assume a low level of fraud in an election at the scale of the American federal election, with so heavily federated a system.
The doubts people have aren't entirely unfounded, and YouTube making an executive decision to perish the thought on their platform only adds fuel to the fire.
I am willing to be "exposed to the idea" as you say. I have to ask which is more likely, a massive undetected fraud across multiple states, or the guy with 40% approval rate losing the election?