Detroit breaks down the numbers by in person votes and Absentee, so that one's the easiest to check.
Detroit had 166,203 Absentee votes for Biden and 6,153 for Trump. That's 96% for Biden Biden.
The "suspicious spike" in Michigan counting was 141,258 votes for Joe Biden and 5,968 votes for Donald Trump. Also, 96% for Biden.
As we've already established, those ratios are typical for Detroit.
It's not implausible at all that the Michigan spike is just Detroit reporting (most of) their absentee ballots.
Why aren't the 4 AM numbers the same as the final count? I don't know. Maybe they can't scan all the ballots and have to hand count some.
I guess it's possible that 25k were faked later. But the mere presence of a Democratic spike isn't proof of fraud. It's proof that Detroit exists, and it's a very blue city.
The "suspicious spike" in Wisconsin was 143,379 votes for Biden and 25,163 votes for Donald Trump. That's 85% for Biden.
Compare to the final results:
https://city.milwaukee.gov/election/ElectionInformation/ElectionResults
Milwaukee went 194,661 Biden to 48,414 Trump. That's 80% for Biden.
The city website doesn't break it down by in person or absentee. I would presume the ratios don't quite match because more Biden voters voted by mail.
The high ratio of Democrats in Milwaukee isn't anything new. This year 79% voted for Biden. In 2016, 77% voted for Clinton:
https://city.milwaukee.gov/ElectionResults1717/2016/November-8.htm
Number of ballots cast was almost the same in 2020 as in 2016.
I could go on. Presumably the Georgia spike is Atlanta reporting mail-in ballots.
Overnight spikes seem to just be a matter of big cities reporting absentee votes all at once. The ratios in these spikes are high because white people in big cities are liberals, there are a lot of black people in those particular cities (who are still voting ~90% Democratic, even after Trump made slight gains), and because more Democrats than Republicans voted by mail.
I'm not sure about the "vote counting was shut down" or "burst water pipe" claims. I haven't looked into either of those.