Replace Fediverse with email. And it would still stand.
Then realize where email is today. Two-three email providers and hosting your own email server grows less and less plausible each day.
My DNS provider offers a free email account for your domain, but that's the easy way.
I rent a VPS for like $15/yr and run everything myself. Setting up an email server takes like half an afternoon if you follow a good tutorial.
I can't say that Gmail being the biggest provider has had any effect on my email server. I'm not really sure how it would, apart from Google deciding to block private email servers somehow.
Receiving is easy. Sending is much harder than it used to be.
Which is kind of the problem, if you need to be approved by the Big guys, there's not much of a point of calling open and fair
You still can host for sure, but the moment M$/Gmail, blocks you, you've lost contact with half the people
That being said, there are production mail servers on OVH (bad reputation mail wise) that deliver plenty of mail to Microsoft, Google and Apple mail servers every day.