There’s one place where it doesn’t (and can’t) help at all: when your address is changing frequently.

Suppose I’m doing some remote debugging stuff on my way to work. I have one IP on my home Wi-Fi. As I walk to my bus stop, it switches to LTE. As my bus drives through the city, I periodically jump to different addresses. I grab a coffee on my walk to the office and end up on the coffee shop’s Wi-Fi with their address. I leave and hop back to LTE, until I get to work and connect to its Wi-Fi.

With SSH, every one of those changes means reconnecting. With Mosh, it means that everything pauses for an instant and then resumes as if nothing ever happened.

Not really, one of the greatest things about mosh is it's ability to restore connections, even if you put your host to sleep, have a network outage, switch from wired to wireless, and the like. The connection just comes back like magic.