Congratulations on getting to a place where you want to drop Google. There
are lots of ways to look at services when wanting one "respects your
freedom". Most of the respondents focused on absolutism, this option is
simply not free (as in cost), which was indicated in your question as a
requirement. Therefore, you are looking for some type of relativism.
Personally, I wish this forum would help people find resources that are
relatively better than what one is using currently; rather than immediately
jumping down some absolutist rabbit hole.
Clearly, dropping Google is a huge step. It can be very difficult as its
services are rather sticky. Moving off Gmail, a service you know for a fact
is mining your email to serve you adverts is a challenge because it requires
using less sticky options. Disroot.org was already mentioned as a drop in
webmail option to replace many Google services. They do not charge, serve
adverts, and are not a hulking corporation with compromised realities.
Beyond that first option, you might already have an account that is free of
advertising that you have more control over. If you have a website, most
hosting accounts include an email account. Openmailbox also has a limited,
free tier. Some people have had issues with the service, but I used it for
three years with no issue.
If your like me, you might have several accounts already, and adding another
might be unnecessary for the purpose of getting away from Google. When I made
that choice, I went back to my old Fastmail account as my primary and use my
icloud account as a secondary account. I went down from a peak of eight
emails accounts to two, meaning less of "me" is out there to be mined.