Nope, they use US providers. The servers are in the EU but the providers are US companies and that means that they aren’t GDPR compliant at all. This is exactly what Schrems II targets.
It looks like this makes Fathom Analytics the only provider for website analytics that you can use if you don't want to maintain a locally hosted version if an open source product – which blows my mind. A small company is the only service that is able to comply with the rules while huge ones simply fail.
I assume that this regulation is also coming to other services soon and analytics isn't the only service that needs to be replaced when a business is in the EU and can't ignore these rules without risking fines. The team at Fathom wrote about alternatives for lots of services here: https://usefathom.com/blog/degoogle
https://imgur.com/a/9wEanqD