I agree, there the theft of the 2020 election was never proven.
It was found by investigators and prosecutors, based on sworn testimony and documents, that these actions around the false slate of electors occurred.
In May 2022, a civil lawsuit was filed against Wisconsin's 10 fake electors and two attorneys who collaborated with them.[68] After more than a year of discovery and filings, the 10 fake electors, including Spindell, agreed to a partial settlement of the case in December 2023. They acknowledged that their actions were "part of an attempt to improperly overturn the 2020 presidential election results."[69] They further stated: "We hereby reaffirm that Joseph R. Biden Jr. won the 2020 presidential election and that we were not the duly elected presidential electors for the State of Wisconsin for the 2020 presidential election. We oppose any attempt to undermine the public's faith in the ultimate results of the 2020 presidential election."
And unlike Trump's legal attempts regarding his claims the election was stolen from him, the main investigation into Trump has not been able to be completed. Remember that whole thing about Presidential immunity? They went for that because of this whole thing about Trump's involvement in the fake electors plot. Unlike the lawsuits that Trump bought regarding mail in voting that went nowhere, this was actually going somewhere.
If you want to give me a source on what you think is the best evidence that the 2020 election was stolen by Demcrats, I would be happy to look at it and then come back to you. All I would ask is that in return, you read 2 chapters of your choice from the Jan 6th Committee report.