Sequoia, a16z, and others are getting into the accelerator game — With YC’s success with Airbnb, Stripe, DoorDash, and others, YC became one of the most popular ways to start a company. By providing advice, brand-name recognition, high-quality access to seed-stage investors, and initial funding — it was a no-brainer to apply to YC. YC had some competition with Techstars, 500…