Instead of switching to Gmail I'd rather think about what exactly makes an email non-personal. For me, it's not about if the senders adress is "name@example.com" rather than "name@gmail.com" but rather what's written inside the mail. Mailgun etc. let you write just normal emails like you would do in gmail as well.
I think the annoying thing about those services is that they are mostly used for mass-mailing. It doesn't matter if you send the same email to thousands of people via gmail rather than anything else - it will still be a poorly customized email for the recipients.