And people change. You don't have to buy it simply because you don't seem to understand how politicized our country has become. You also don't seem to understand that Biden changed strategy from past Democrats, such as completely disregarding Ohio, figuring he couldn't get the win there, and concentrating on the 3 states that were the tipping point for Hillary's loss in 2016, Michigan, Pennsylvania and Wisconsin. NC was even seen as a swing state (still not enough techies to overcome the redneck, aka people who raised me, votes here, yet, although seeing the posts on FB from my High School friends gives me hope). Arizona and Georgia were seen as possibilities for different reasons but have become swing states.
Of the 19 places in the US that usually correctly pick the president, only one got it right this time.
www.bbc.com
There is no other way to explain it to you besides "things change". How anyone can expect things like voting preferences and populations to stay the same for that many decades is just ludicrous. People and places change. Even strategies change. Who a group decides to actually pander to for votes changes. Even Trump changed the political strategy of the GOP since the previous 2-3 decades before him, by going straight for the actual conservative base, pretty much saying **** you to Independents and moderates, and making promises and giving compliments and passes to extremists. Hence why we have Q, why he has not gotten above 50% positive polling since his inauguration, but still maintains a pretty large loyal base (I've never seen any group more loyal to a politician than Trump supporters). That changes things. And in fact, Trump himself caused some of the change for bellwether counties. When you demand loyalty from people, the majority will either give it all or completely turn away, seeing such a demand as unreasonable, hence why they shouldn't vote for you.
There was no fraud. Simply because you think large counties, with large democratic populations who also made it somewhat easier for their people to vote as well as, in the case of Georgia, to "cure" their ballots (this was actually a law changed in 2019 for the entire state, which Dems prepared for and GOP didn't) committed fraud doesn't make you correct. There is no credible evidence of fraud.