I use several email providers. Some are leftovers from different times/situations, some are for different uses. But, anyway, whatever service provider you pick, you can get “privacy” because messages are encoded while they are transmitted but you can’t get “privacy” once the messages are on the provider’s server. In short, the provider can access your messages.
The other option is to host your own mail server and use something like PGP for message encoding (which has the drawback all your contacts need to use PGP as well).
Oh, I forgot. In my experience the worst issue is you gave your mail address to many people (work, friends, doctors, public services, etc) then you change provider and you cannot keep the same address. So it is a good idea to plan for the long term.