You can do calendar and contacts separate from email. Try Radicale. I’ve been using it for years.

Another container-based alternative in that space is Mailu.

Look, I appreciate you pushing on the UX aspects of the fediverse here. But let me ask yout something. What’s your email address? Is it Lost_My_Mind? No? Oh, because it’s got an @whatever.com on the end? Why is that? Why don’t we have one global, centralized namespace for email usernames such that there’s only a single Lost_My_Mind in the whole world?