I used to use gnupass and its variants (including passforios on mobile), but what brought me to bitwarden was being able to make changes on two clients and merge the results cleanly / usefully without needing to do anything manually at all.

How does this work with keepassxc? Does it depend on your file syncing primitive?

When I stopped using KeePassXC, there was no merging. You configured each client to save immediately and reload when detecting the file changed. If you used a tool like Syncthing then you had to monitor for conflicts (which stopped syncing) and manually fix them. If the major clients on Linux, Android, and browser extensions all supported proper syncing on their own, I might switch back.