Your credential manager provides this sync and backup capability. There are dozens of credential managers available that work on all platforms. You don't have to use the default one on any given platform.
When was the last time you used a library computer, let alone logged onto a private service with it? This was a bad idea even 20 years ago. In today’s security climate, aw hell no.
Or my sisters laptop. & Fairly recently actually, to print something. Most accounts I don’t care that much about & two factor should be enough to save me I hope.
Bitwarden is my personal choice.