There were a number of online eyewear stores that sold online only direct-to-consumer glasses before Warby Parker in the “upscale” price range of $100 GlassesUSA.com (2007), ~ 45% of SKUs are private label Glassesshop.com (2004), ~ 90% SKUs are private label

and many more online stores that sold even cheaper private label RX eyewear: zennioptical.com (2007), 100% SKUs PL, price range $6-45 Eyebuydirect.com (2005), 90% SKUs PL, price range $6-45 39dollarglasses.com (2000), 100% SKUs PL, price $39-109

So, at least part of your argument is unjustified. The guys at Warby Parker created a very unique product perceived at the edge of cool/”retro-intellectual” / boutique-quality / affordable / with a noble mission. That was unique.