I use atuin for the shell history as it seems to know when I've run a command in one tab/split while another is open where fzf doesn't seem to sync it all the time. But I still use fzf to find files.

(Bonus, I use Zoxide to replace the alt+d cd shortcut as it's much faster, and use https://github.com/Aloxaf/fzf-tab for tab completions in the terminal to become fuzzy, very very useful)

Atuin also has syncing and backups though I've never really felt the need to use it. I prefer keeping histories separate and when I need to share shell commands I just do the usual methods like putting it in a shared text file, send it to myself on a chat app or just looking at the command and typing it out