At the same time, in recent years, I've found that ssh running on top of Wireguard / Tailscale is way more usable than 2013 days. Those latter tools address the roaming IP issues directly at the network layer.
So while there are still issues with ssh / TCP if you're on a really crappy network (heavy packet loss, satellite link, etc), those have been less common in my experience compared to IP changes.
The “killer use case” for Mosh feels a lot less killer now.