My advice (which of course comes with the caveat that it's from a random Internet stranger so objectively not backed by anything) would be to focus on building

My advice (which of course comes with the caveat that it's from a random Internet stranger so objectively not backed by anything) would be to focus on building up traction, figuring out small-scale funding now if that's what's keeping you from focusing on this company, and then applying to YC some time later when you're so busy with the company that you feel it might actually be better if you don't get accepted. Investors want to invest in businesses and founders that aren't desperate for their money and connections.