And it can already read the 1Password .opvault (the "legacy" format, stored in Dropbox and on disk) "file" format -- I would guess it wouldn't be an unholy amount of work to teach it to write out that format, too, but I stopped short of doing that work because I figured KeePassXC wouldn't merge it

After that, I would teach KeePassXC to serve the 1Password browser extension websocket protocol, because I found its UX far, far, far, far superior to KeePassXC's browser extension UX

I have tried it, but one of my use cases is sharing passwords, and I couldn’t figure out how to do that well.

And you can choose to sync with Dropbox, one drive, etc. And it has an android app.