I believe what they’re getting at is an issue if they’re not already authenticated prior to the outage. Then they’d have no access to their media unless they look into the workaround for that beforehand. It has been an issue in the past, especially when Plex’s auth servers go down. I remember plenty of Reddit threads complaining about it.
I use a Garmin Venu 2. It’s a “smart enough” watch where it’s not annoying in terms of notifications, but it provides all of the data I could imagine needing relating to my fitness activities. I started using it after Mozilla reviewed Garmin’s stance on privacy.
I also have a Seiko kinetic watch I wear for nice or more formal events.