Isn't it? Isn't the problem that the data is sent to a third-party service outside EU (in the US) that doesn't offer the same data-protection rules as EU?

nope, it's that the legal entity is required to honor US warrants. EU wants full control over that process.

I don't get your point, are you saying that the solution as webmaster is NOT to use a self-hosted solution, but to just sit and blame the EU/US legislation?