This means that sending data from the EU to a US company is almost always a GDPR violation. There are a few nuances to this which are very important.
- The US CLOUD Act gives US law enforcement access to data stored in other jurisdictions. This means that locating the servers in the EU is not sufficient. Nor is operating via an EU subsidiaries.
- IP address counts as personal data, as does pseudonymized identifiers.
The two of these combined mean that GDPR forbids you from having your users connect to Google servers. This is why Google Fonts is straight forbidden, and why most installations of Google Analytics are forbidden. Also the use of basically anything from Google, Azure, AWS, Oracle, Facebook, Akamai, etc except when routed through an EU proxy which obscures the user's original IP address.