So yes. Magic could likely give someone 20/20 vision. It could likely give someone bald hair. It could likely untwist spines, give people limbs who were born without them, and anything else you want it to do.
That doesn't mean we should see it as a world-building flaw that powerful, wealthy, beautiful people might have scars/glasses/missing limbs/need glasses.
Exactly. How exactly restoration magic works for various edge cases is up to the GM and players.
For some of your examples, we don't need any explanation other than vanity. In real life, wealthy, powerful, handsome young men would GIVE themselves facial scars (google "Mensur scars", "the bragging scar", "smite", "Schmitte", or "Renommierschmiss").
I started needing reading glasses a few years ago. I had better than average vision for most of my life. I still have excellent distant vision. There is this magic called "LASIK surgery" available to me, which I could easily afford. Now, maybe it is more of a hassle than a restoration spell (but who knows, the RAW have nothing to say about whether the process is painful, etc.), but it is about as easy as a medical procedure can be. But I see not reason to bother. I don't see it worth the money. (As might a wizard, 100 GP is 100 GP after all, and how easy it is to procure diamond dust is a world-building decision). But, even more importantly, I find that wearing reading glasses, especially blue-light glasses, make the long hours I have to work on the computer (and discuss glasses on EN World) much more comfortable. My eyes just don't get fatigued like they used to. Wearing reading glass even if you don't need them to reduce eye strain is something people do in real life. Maybe reading arcane script and diagrams is even more taxing on the eyes.
I don't know if greater restoration would restore congenitally missing limbs (I'd rule not), and I'd expect that most people who lose a limb in battle are from an accident would be much more likely to restore that limb if they could. But in real life, there are some people who want to (and do) cut off normally functioning limbs.