Would hosting in Europe really help? I’m under the impression that current EU case law makes it impossible for EU-based government entities to store personal d

Would hosting in Europe really help? I’m under the impression that current EU case law makes it impossible for EU-based government entities to store personal data in services owned by US entities, no matter where they are hosted. Maybe I misunderstood this? Someone has told me that all the EU governments using Office 365 are basically violating the GDPR and getting away with it (for now). Any truth to that?