That's not true. No one disputed the actual results or claimed it was actually stolen. Virtually everyone agrees with the actual counting of the votes (no votes were added, changed, or thrown out).

People were saying there was interference from, and collusion with, Russia. Those actions would be illegal in their own right and would have influenced the outcome of the election, but no one said the actual outcome of the election should be overturned.

It would be like if I kidnapped you on the morning of the election, and didn't let you go until after so that you couldn't vote. That kidnapping was illegal. And it certainly affected the tally of the votes. But that doesn't mean that the results should be overturned or that you should be allowed to vote retroactively.

The difference is that there are plenty of people that say the actual outcome of Biden's election was wrong. That he actually "stole" the election. That votes were directly tampered with. And it's not just a couple of crazies that are shouted down by the "sane" Republicans. There's a huge portion of sitting Senators and Representatives and Supreme Court justices who believe this crap.