The problem with having your own domain for email is the communication factor. When I tell someone my email is charles.lastname@gmail.com, there's no miscommunication. Worst case I have to spell out my last name, but generally if someone's asking for email they already have my last name.

If you buy a domain, nowadays, you have few options with respect to getting an email that sounds legit, mature, and isn't long and/or uses easily misspelled words.

I have a bunch of domains, but none of them are particularly appropriate for an email address I would verbally communicate to someone. bluh.org is my main domain, but when you say 'bluh' out loud to someone, you inevitably have to spell it. I once owned thereisnocharles.com, which was a goofy thing and I used that as my main email address before gmail came along. But it's long, and it doesn't sound professional at all.

I guess we could all just use something like gmail as a simple forwarder service to our owned email addresses, but even then, it's not a foolproof solution.