For example, implantable contact lenses are commonly used to treat myopia. The lens is implanted in the eye over the long term, no infection. There’s no reason why this isn’t feasible for contact lens screens. One could posit that people won’t want to implant a contact lens screen in their eye, and perhaps they won’t, but it’s up for debate and perhaps underestimated how readily many people dive head first into scary new things (think, say, how many used LSD in the 60s).
Even if the lenses weren’t implanted, it’s still feasible for disposable contact lens screens to be cost-effective. You can buy all types of screens right now for less than a dollar. It’s not impossible to make cheap disposable screens for contact lenses.
Again, there are difficult problems to solve here, but I think calling it a technological dead end underestimates just how novel and clever humans can be to make things work.