You mean no one who is sane believes Joe got 20 million more votes than Obama.
It's easy to believe that Biden got more votes than Obama. Because Trump is the most hated President in American history and Biden is a moderate who got a whole lot of independents and Real Republicans.
What is hard to believe is that Trump got 12 million more votes in 2020 then he got in 2016. Lots of people who voted for Trump in 2016 did not vote for him in 2020. There are very, very few that did not vote for him in 2016, but did vote for him in 2020.
If there was any election fraud, it was an inflated count of Trump votes, not Biden votes. I estimate that there were no more than 60 million votes for Trump in 2020. Trump just can't believe that he lost - even when he cheated by about 13 million votes.