A user name is usually requested when setting up general online accounts, using ones email is a common practice. Is there a better or more secure practice?
In process of changing to a new email address, found that it might’ve been better if I didn’t use my email as username. From one’s email to a simple phrase or strong random pin or pass code, what is best practice, are there security advantages?
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Pat Maxim
In many cases the account ID and email address are the same thing. You have to use an email address for your ID. That's because email addresses are unique and a good way to contact you if you need help (password resets).
In rare cases when you can have another ID in addition to your account email address, those are often public things that others can see. Like Twitter or Reddit handles and such. Of course you wouldn't use your email address for that. But what you do use depends on how you want others to be able to see/find you.
Security is all in the password and two-factor authentication. Any site/service that offers a different ID than your email address will also have your email address as an ID option (password resets, etc) so there's no security to be gained there. Maybe some privacy advantages to having an obscure ID, but that depends on the site/service. What you choose as an ID in these cases really depends on the service and how that ID is used, and what you want to get out of the service.