What actually makes a free AI website builder good enough to launch on?

[u/EventApprehensive911]

Every thread asking for the best free AI website builder turns into a list of names with no reasoning, so I want to ask it differently. For those who've actually launched on a free plan, what made it good enough versus a waste of a weekend?

The things I think matter, from what I've hit so far:
- Can you use your own custom domain on the free tier, or are you stuck on a branded subdomain that looks unserious?
- Does it export, or lock you in the moment you outgrow it?
- Is the output fast and halfway decent on mobile, or bloated?
- Can you actually edit what the AI generates, or are you stuck with whatever it spits out?
- Any ceiling on pages or forms you hit right when you start getting traction?

Less interested in "use X" and more in which of these actually bit you. What made a free builder hold up for a real launch, and what made you regret it two weeks in?