Infrastructure is difficult. I have to run 2 ISPs these days. FTTP and DOCSIS.

The fiber line is obviously my primary and it's completely flawless when it's working. The problem is that about once or twice a year a utility contractor will break the fiber in my neighborhood and it can go out for up to 2 days. Cellular service is not sufficient to cover. The cable connection is what I use when the fiber goes down hard like that. I don't bother with a multi-WAN router or anything. It's a manual cutover thing. The cable can obviously go down too, but it follows a different path (power lines vs buried). The cable is more likely to go out, but it can be resolved more quickly assuming a localized incident.

I was looking at using starlink for backup, but there are caveats with satellite connectivity in the woods.