Well, what you're not saying is that providers subject to US law cannot guarantee that European citizens' data will be protected from being passed on to the US government (see Golem and FR Sénat).
I can't say whether a provider such as Hetzner, which is certainly smaller than Azure, AWS or Google Cloud, could currently be a sufficiently high-quality alternative for you. I suspect there must be other providers like this in France or Finland or elsewhere in the EU. I also realise that migration would be costly in any case.
I just think it would fit in well with your initiatives such as HDM Secure if you could also offer a suitable Joplincloud service under exclusively European law.