I've hosted my own email server for almost a decade now.

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.