I question whether a lot of people even need sync.
Passwords in general don't change for long periods of time. Really the only rationale for doing so is confirmed or suspected compromise (two-factor processes make this rarer still). It doesn't strike me that an almost permanently static input merits regular synchronization.
The alternative is doing a one-off manual sync (copy and paste) between two local DBs, then locally moving one of them to the target device. Zero online connectivity has to dramatically reduce attack surface. Is five minutes' maintenance per year an unacceptable convenience penalty to pay?