The election process requires a voter registration system, a pollbook, a voting system and tabulation/reporting of the results. The US election system is very non-transparent and is subject to manipulation and fraud at every level. Some states have people on the voter registration rolls that are 150 years old. Many problems exist, just with voter registration and the pollbooks.
In the graphic below you can can steps in the voting process. Each of these steps has documented problems leading to voter fraud, and the graphic does not even include the problems with voter dropboxes that were so massively abused during the last election. In many cases, the problems are very big (hundreds of thousands/millions of votes statewide) and subject to non-transparent manipulation by the local and state officials. It appears the voting machine software is written to keep two sets of books. One is for public consumption to show only what the designers wish to be viewed and it is essentially not auditable. The second set of books can be manipulated by the software and even by remote sites logging/hacking in to the voting machines. In Ohio the local machines are dirt simple and do not appear to be that susceptible to manipulation except at the state level during the tabulation and aggregation processes where the processes are completely opaque, are connected to the internet, are not auditable and are firewalled against any citizen access or any accountability to any governing authority including the Attorney General and the legislature. In 2020 election the process was so bad that there were more total votes cast than there are registered voters. No computer voting system is ever likely to be safe from manipulation, because the process is inherently non-transparent. A simple paper voting process with votes publicly counted at the precinct level and subject to audit and recount for a very minimal fee is easy to create. Taiwan has a system where the votes are counted at the precinct hall in public. The counter holds up the ballot and calls out the vote. The vote called by the counter is subject to challenge by anyone present. There is no reason we could not clean up our voter rolls and have paper ballots that are publicly counted at the precinct level. Such a system is MUCH, MUCH less subject to fraud than the current opaque and fraudulent voting system that is stripping away our constitutional rights and our republic, as the last "election" clearly showed.