maybe using hashed receipts things -- better identity proofing, things like that
I don't think you fully understand the problem.
If you give people a receipt of some kind that can be used to check who they voted for, you've broken anonymity.
Another huge fundamental problem is that digital tallies cannot be directly observed. Physical ballot boxes can. The ability to directly observe the entire process is absolutely critical. As Germany's Federal Constitutional Court found, "the inability to have meaningful public scrutiny meant that electronic voting was unconstitutional".
These are unique problems that cannot be solved with things like "receipts" and "better identity proofing".
who is to say better methods won't be thought of
Me, and I just explained why. Also Germany, Canada, and many other countries. Also every cyber security expert on the planet, give or take.
paper ballots are highly vulnerable to cheating
False equivalence. Physical ballots are not as vulnerable to large scale tampering as flipping some numbers in a computer.