GDPR Art 83, §1

Effective, proportionate and dissuasive fines are widely understood under common EU law that the fine may not bankcrupt a corporation, if it does for whatever reason because it's too high, you can seek legal remedies against the authority as per GDPR Art. 78

And that is only the GDPR, there are similar provisions in all EU member countries.

The exception will be, of course, if you caused economic damage to users or others, in which case you'll have a case at the regulator and a court case will be opened too, both of which are independent and the court case can certainly bankcrupt you if the damages far exceed what your company has in assets (in which case your company will be forcefully dissolved and that's that)