You have correctly identified Luxottica's value proposition: "You don't know how to get into eyewear, but we are experts on it. Partner with us!"

However, to even move the needle for Luxottica, that brand partnership has to be worth many millions of dollars.

Warby Parker is not competing against Luxottica. They are not trying to do white-label eyewear for other fashion brands. Warby is simply another fashion brand. They are competing with the other brands that Luxottica is making glasses for.

There is another company (which I used to work for, called Eponym, Inc.) who is a closer competitor to Luxottica in terms of trying to capture the market of fashion who want to get into eyewear. Though the success of selling glasses to individual customers is important, Luxottica is more of a B2B partnership whereas Warby is B2C.