[Arrath]

To be fair there are differences in condition when someone 50/60/70+ gets a hip replaced and someone in their prime having it. The former will have had decades more wear and tear and overall degradation on their joints that the latter will not yet have had. The distant memories of what their hips were like may be faint enough they don't even really recall whether its better or not.

Anecdotally I've also met older folks who expressed wishing they'd done it sooner for knee/hip replacements. I also have a friend with a health issue that required both hips replaced at 25, and they expressed frustration at the recuperation and physical therapy process, and they dread the fact that they're young enough for the hip replacements to need replaced themselves in a few decades, an issue the older recipients generally don't have to worry about.

Anyway, that's just a long way in saying, "Do we have bionic hip implants 125% better than natural that anyone with means should get if they want?" and the answer being "Not yet"

[hotpotamus]

You've hit the nail on the head. I also have a childhood hip condition (Perthes disease) that has had me looking at hip replacements since my 20's and having the same fears as your friend.

Looking at pro athletes is sort of instructive; essentially none of them have returned to play after a hip replacement (Bo Jackson kind of, but in limited capacity). A few, most famously Andy Murray, have returned after hip resurfacing, so it's probably about as close to a natural hip as possible, but likely still a bit inferior.