You could ride quite some distance on pitted races if necessary. However, pitting the races is rare if you keep maintenance up. Periodically clean and pack the grease. Replace pitted cones as soon as you discover them. Keep cones adjusted properly.

I'm not sure why sealed bearings haven't had wider acceptance. Certainly some brands have been using them for decades. And, of course, they do also wear out eventually. On a global tour, you could bring the spare cones for a standard hub, or spare sealed cartridges for a cartridge hub if you wished.

Some of the newer Shimano hubs use an oversized cone that isn't readily available yet.