With the recent articles about Proton supporting French right-wing candidates (from what I recall) individuals were mentioning how great Fastmail is as an alternative. That's my best guess at least

What does this even possibly mean? Fastmail has employees in the US, Europe and Australia. As far as I can tell with a warrant the government of any of these is likely to get a response from fastmail, just like if the government had a warrant to search my storage unit or review my bank statements. I don't understand the point you make. either there is rule of law or there isnt.