Anyone actually gotten stuck because they couldn't get their code out of a platform?

Most of the vibe coding conversation is about speed and quality, how fast you can build and how good it turns out. Nobody really talks about the exit question. If you build inside a platform that hosts everything for you, how easy is it to actually leave.

Some tools give you a clean codebase you can download and run anywhere. Others keep the important parts, database structure, auth, backend logic, wired into their own infrastructure in a way that's hard to fully untangle. You don't notice this while things are going well. You notice it the moment you want to switch tools, bring in an actual engineer, or move to your own hosting and suddenly realize how much of your app doesn't travel with you.

Has anyone hit this wall for real. Did you end up rebuilding from scratch somewhere else, or did you manage to get everything out cleanly. And if you checked this before you started building, what did you actually look for.