The problem is if you're at a startup you probably don't know what your product is, because you don't know who your customers are.
My last startup died because we committed too hard to the product and the business model, which while innovative and one that I still believe could have succeeded - we utterly failed because we didn't understand our customers and we didn't pivot fast enough, ran out of runway and then everyone but the founders got laid off. Waiting on hearing about the equity.