For thirty years an unfinished product looked unfinished. Placeholder text, a broken link, a login button that did nothing. You could tell how far along something was by looking at it, and so could everyone else in the room.
That signal is gone. A founder can describe a product on Friday and open a real URL on Monday: working sign-up, a dashboard with live data, Stripe taking test payments, a domain with a certificate on it. It looks finished because in every way a screen is capable of showing, it is finished.
What a screen cannot show is authorization, tenant isolation, rate limits, secrets handling, backups, migrations, audit trails, observability, or what happens the first time an integration times out halfway through a transaction. None of that has a visual state. It is either there or it is not, and the demo looks identical either way.
That is the real shape of the prototype-to-production gap. Not that it is large. That it is invisible, and invisible specifically to the person who has to decide whether to launch.