In that episode of the Orville, Gordon was able to get a new foot grown fast enough that it wasn’t really an issue.
In contrast, in TNG, Worf sustained an injury from a relatively minor industrial accident which left him paralyzed and could only be fixed by a radically dangerous and experimental medical procedure. In Voyager, Vidiians stole Neelix’s lungs and it took a Vidiian to alter one of Kes’s lungs to become compatible.
I don’t think the Federation’s medical technology is that advanced, especially with the banning of genetic manipulation.
Edit: And here I am forgetting about Nog’s amputated leg, which was not a perfect regrowing and caused Nog to experience phantom pain from his severed limb.