I use Tuta combined with Addy.io, and it's been great. I never hand out the main email at Tuta, and if I ever want to pack up and move, I just tell Addy to change where to forward email.
I don't think you need to worry about Tuta. Iirc, all of the encryption/decryption happens on your device, so they can't see the content of your inbox, even if they wanted to. Their free tier is enough for me, and I just make sure to clean out any unwanted emails so I don't hit the 1GB limit.
Now, there's the caveat that encrypted email needs to be able to work with unencrypted email, so somewhere along the way, it's possible somebody could figure out who you are and what you're talking about by intercepting traffic or the endpoint, but if you need that level of privacy, email shouldn't be trusted anyway.
The biggest benefit of encrypted email is a judge can't force the company to hand over your inbox (because it's encrypted), and you don't have to worry about the parent company or whoever data mining it. But even if it's in a country that could order data collection, and you "aim to misbehave," I think it's moot, since you should know better than to use email for that purpose.
If you're willing to pay for it, Mailbox.org would be my choice. No provider will give that feature away for free (which I'm sure you know). My threat model can tolerate an extra hand via Addy, so I don't mind them being there.
But no matter who you choose, email just isn't the best option for true privacy. There will always be some cleartext email somewhere in the process, even if only sometimes. And as somebody once said, "No company is going to break the law for you."
If you need an extra level of privacy with email specifically, your best option is to self host. That way you control both the server and the database/storage.