Another thing to remember when pontificating about why mugs like me spend a fortune on glasses, when we could be getting a couple of 2 for £20 quid jobs off the internet with the optical centres in the wrong place, the wrong pantoscopic tilt, the frame unfitted, etc. etc., is that for some prescriptions, your frame choice is extremely limited.
I don't trip joyfully around the shop picking frames from here and there at my whim, selecting a rimless frame here, a stylish flared frame there, a budget-conscious but perfectly fine frame here, a slightly more dressy pair there.
No — through a long and tedious set of interactions with the DO, I eventually just get told, "Here — these three randomly-priced frames are the only ones we have which will fit your lenses without looking utterly ridiculous, weighing half a kilo, wasting all the money you spent upgrading to higher-index lenses to get thinner edges, and/or being actually technically impossible".
Well, I say random. They're never the £29 frames.