That’s a very legitimate question. You can read in our FAQ our commitment to enabling people to migrate off us if something happens to Bubble (section ‘Data Ownership and Exporting’). Essentially:
Bubble apps can only be run on the Bubble platform; there’s no way of exporting your application as code. If you decide to move off the Bubble platform, you’ll have to rebuild the application logic, although we can help you export the design. We’ll do our best to help you leave if you want to. Our goal, though, is for Bubble to grow with your app; via our javascript and API integrations, you’ll never hit a hard limit of the system, and we plan to keep our pricing competitive with the cost of building out your own engineering team and infrastructure.
Finally, we want to make sure you feel secure about building on the Bubble platform, so, although we plan to be around for a very long time, here’s our guarantee: if we ever for some reason have to close down shop, we will release the Bubble source code under an open-source license so that you can set up your own Bubble server and keep your app running.
In terms of exporting data, you can already export as as CSV/Excel, and we recently opened an API which lets you get all your data out in a programmatic way if needed.