I'm not a conspiracy theorist, but I'll just make these observations.
Arizona was called early on election night for Biden by Fox News, with a large percentage of the vote uncounted and Biden without a huge lead.
Michigan and Wisconsin had Trump leading in both states late Tuesday, early Wednesday; in the morning Biden was leading.
Pennsylvania's attorney general (the top law enforcement official in the state) tweeted out before the election that there was no way Trump would win the state. IIRC, Trump led the vote count until Friday when Biden took the lead.
Here in my state of Georgia, a local station was doing election coverage and early Wednesday said based on Trump's lead and the amount of votes remaining to be counted, he couldn't see how Biden had a path to winning the state. Friday, Biden took a slim lead in the vote count. I also heard Fulton County (which contains Atlanta) sent home Republican poll watchers late Tues/early Wed with the explanation vote counting would resume in the morning, but kept counting votes early Wednesday morning.
In several close states with ballots counted after early Wednesday morning, votes went for Biden at an unnatural rate. Add to that the fraud inherent in mail in ballots (not absentee but mail-in) and you can understand why the integrity of elections anywhere, and now in the US, are undermined.