I think a little care should be used when applying the term "voter fraud".
When I use it, it means voter impersonation. There are many other crimes associated with voter fraud such as fraudulent voter registration, or illegal harvesting of ballots. Sorry folks but Mickey Mouse is not a resident of the US and therefore can not register to vote in a US election. However, the person who registered Mickey Mouse to vote committed a crime. The upside is Mickey Mouse did not show up to vote for Biden ... or did he?
There are as you typed very few cases of actual, real cases of voter impersonation at the polling stations. All of the known cases from the 2020 election (of which I know) were perpetrated by Republicans voting for Mr Trump. There are far more cases of voter registration fraud, illegal harvesting, and felons voting than voter impersonation. A strange note regarding registration fraud is very few people named on the registration card show up to vote. In other words someone has registered dead folks, imaginary folks, cartoon characters, or pets. Clearly these entities named did not vote. Try telling a Trump supporter Donald Duck did not vote for Biden.
just some random thoughts