There was definitely some fraud - there's always some fraud, and there have been confirmed cases of fraud in 2020, IIRC there was at least one person who got caught for it in 2020. Was the fraud enough to make a difference? I don't know, and I don't really think we can know. In 2020 there was an unprecedented switch to mail in ballots, which are inherently more vulnerable, Trump inspired such hatred from the establishment and liberals that they would have done anything to stop him, and dems propagandized for months trying to give themselves an excuse for why the election results couldn't be trusted on the day of but might change in the days afterward, but as far as I'm aware we've seen no rock solid evidence that the fraud that occurred swayed the results.
End of the day who gives a shit? Imagine getting to the door on Flight 93 and going "Wait - it says do not enter!" The election was fake and gay, not just because of potential falsified votes, but because of the courts and and a federal bureaucracy which have de facto legislated contrary to both the will and interests of the people, both in 2020 and for years before, and past legislation that was forced on the country by a legislature that lied and schemed because they had decided that, their constituency not being to their liking, they would replace it. The 2020 election was illegitimate because every American election going back to at least the 60s was illegitimate.
"Well, as long as our country is stolen from us LEGALLY."
That said, there's not going to be any overturning the 2020 election or "reinstating" Trump, and it's pointless and counterproductive to wish there was. Resisting the effort to oust Trump would be mechanically the same regardless of what the "legitimate" result would have been, and would only have been possible with deliberate effort and planning and loyal allies while Trump was in office, if it was possible at all. It's certainly no longer possible. There's not going to be any magic Space Force generals descending from on high to arrest all the democrats and reveal that Trump was actually the president this whole time, if only people Trust The Plan enough. We need to move forward with a solid understanding of what is currently possible and what needs to become possible.