I think the main question is what kind of alternatives are you looking for. Calendar service is provided by most of these companies already. Anyway I'm not sure

I think the main question is what kind of alternatives are you looking for. Calendar service is provided by most of these companies already. Anyway I'm not sure who qualifies as privacy-first provider. E.g. Zoho has a quite good privacy policy at first glance: https://www.zoho.com/privacy.html https://www.zoho.com/privacy.html Is there even a difference between main Google PP and G-Suite PP? Is Office365 PP privacy first?