I’ve been with tuta using a custom domain for a couple years now. Started switching most my services away from Google et al for pro privacy reasons a long time ago. It just so happens that these kind of decisions end up with the same results as moving to EU based solutions.

I feel like for most people their email account is just somewhere their emails go. And trust me there are plenty of options out there. If Google Calendar etc is something that your missing, then look for a alternative calendar service rather than an email service.