As a founder of an early stage startup, YC just seems much less compelling than it did, say, 5+ years ago. If you aren't far along yet, makes sense to submit an application for the same reasons you might buy a lottery ticket, but if you're further along, what it takes to be truly competitive seems identical to what it takes to just raise an early round.
I think YC is a huge positive macro force in the ecosystem, but on a micro level it doesn't seem clear why applying makes sense anymore.