How much equity are you offering?
A developer can get any job and be paid relatively well. You’d need to convince someone to invest their time in this product so that it will perhaps grow and be worth something, most likely it will end up being worth nothing, therefore people will rather work for real money rather than equity.
Then you’re not doing the proper fundraise and investors will care. If you don’t raise enough money to pay all of you decent salaries then you all will not be focusing 100% on startup and that might be a red flag for a lot of people.