The concrete job here is not "make me a landing page." It is building a small business web app with login, CRUD screens, and per-user data isolation that should not fall apart the first time requirements change. v0 and Softgen genuinely diverge on that job because one is primarily a code-generating UI tool and the other aims at end-to-end app generation with backend pieces included.
That difference exposes the failure modes that actually matter. A pretty screen is recoverable; weak auth wiring, unclear data ownership, or generated backend logic that nobody can safely maintain is not. Judging them on a business app forces the comparison away from demo quality and toward security-sensitive plumbing, iteration cost, and how much of the final system you really own.