i don’t think you can conclusively say there wasn’t something fishy about the 2020 election. the 2016 election was considered “stolen” or “hacked” by the losing party that year too
If there was something fishy there would be evidence wouldn’t there? The DOJ said there was no rampant voter fraud. Every election will have some votes that are off, but when it’s not enough to sway the election (by even a close margin) then I don’t think it rises to the bar of suspicious. In 2016 there was not any coverage about the election being stolen, nor people attacking congress to try and overturn an election. There was a large discussion about polling and how they were so off. Also outrage about how the electoral college works (same thing in 2020). Maybe if you look at the media on the extreme sides you have a different picture, but I would say the sentiment after 2016 was more shock (once again because of polling).
I think every election is going to be fishy in the sense that the biased media outlets break stories in ways to manipulate voters towards one outcome or the other. Making voting more accessible to people with mail-in ballots will have had some affect, too, and most likely helped the democrats, just like closing polling stations and under-serving voters has helped the republicans in some cases. But was it cheating, or stealing? I don't think that qualifies at all. I definitely don't think the pandemic response and mail-in ballot measures were primarily some scheme to get more D votes. I wouldn't call Trumps 2016 win illegitimate either, but all the fake news coming from russian owned blogs and sockpuppets and targeting vulnerable voters was still something we needed to make a stink about and work to mitigate.