We “only” have ~35Mbps upload, but that’s plenty since the initial backup was the only large transfer. Daily backup transfers are generally pretty small for me.
But getting the initial transfer done locally was definitely important for my use case!
You probably don’t generate more than 4 megabits of backup-worthy data on average every second
Exactly — this is ~10GB every 6 hours (which is probably a reasonable amount of time to run a backup while not interfering with active Internet use).
Basically the only backup-worthy content I generate is casual photos and videos, and these are nowhere near that size (Immich database backups also take up a bit but I could certainly be smarter about how I handle these backups).