Getting something up and running is often waaaaaay more valuable then achieving Stripe level UX from the outset, and then as time progresses you must make a conscious effort to improve. Remember, Stripe has been an app for about a decade. That's a decade's worth of learning what users care about and what details matter. And clearly that's a decade to polish a product to near perfection.
A trap I've fallen in myself, and I see /a lot/ is that people focus on delighting their users before they even know what delights their users or what their users care about. Often you'll only learn that by having a product that works and customers need from the outset.