You know, I wonder that too.  I see articles occasionally where voter rolls are being scrubbed or ordered scrubbed by courts.  In Wisconsin, I think it was 235,000 (maybe more) registered voters removed from the rolls because they did not respond to queries if they were still living in WI.  That's great work.  I know in CA Judicial Watch had something like 1.5 million removed.  I am still deeply concerned, as you are, about voter fraud.  There is a book by Eric Eggers, the research director for Peter Schweizer's organization (Government Accountability Institute)  about voter fraud in 2020, titled, "Fraud".  Haven't read it yet.