Have you tried Syncthing?
the ONLY thing that's worked for me is syncthing -- I can't copy files over USB reliably at all.
I guess I could also pay for google photos but honestly fuck google so much. I have a pixel 3a so all I get is the unlimited low-res images.
Why the hell this thing can't just backup files over USB or SMB or a card reader/USB drive plugged in to usb-C is beyond me.