Hillary won the popular vote, and Comey's announcement 2 weeks prior did her in. That and overconfidence, taking various states and demographcs for granted and not bothering campaigning in them, and the simple fact that the problem with Bill Mach II was that she wasn't Bill, and many people simply didn't like her.
Trump & family were totally suprised that he won, as even they didn't expect it, and Melania opted to stay in NY for months, hoping she'd wake up and the joke would be over.
There was no steal, Trump lost to Covid and to Biden campaigning in the very states Hillzy ignored, them in fact being his core base to begin with. Attempts to stop huge swaths of people from voting bakfired bigly as well, just like it did in 2012.