My Mac tells me 5+ times per day that it's unable to backup something or another because I'm not logged into the Apple cloud or whatever it's called. And there's not obvious way to make it stop.
If you don't want to receive notifications from iCloud, go into Notifications in the System Settings and uncheck the box next to iCloud in the list of what is allowed to send notifications.
How do you do you block One Drive on Windows from nagging you constantly?
You can't turn off notifications on MacOS AFAICT, but you can set "quiet hours" to 24 hours a day. So now I only see any notifications if I happen to be using my computer at exactly 10:00 pm.
If you have any notifications you actually do want, this isn't a viable solution. But personally I have yet to ever see a notification on my computer which I considered important.
I don't run into that, but I do have an iCloud account and I'm logged into it, which probably helps. I'm logged into my Microsoft account on Windows, too, but it is still pushy.
This is not unique to Windows.