Using iCloud mail as AppleID login?

https://programming.dev/post/788988

Using iCloud mail as AppleID login? - programming.dev

Is it safe to use iCloud mail as login for AppleID? I created my apple account originally with gmail, but I’m slowly transitioning out of the google mail and am considering changing my Apple ID as well. But given that the mail is part of the account, is it safe to use it? Are there any guides how to best secure account while using icloud mail? Having a different mail as backup for recover? Something more?

You can’t use iCloud mail as Apple ID [update] You can’t setup an iCloud mail when you submit, after three months it is possible to change.
This is true. My Apple ID is iCloud, switched it from Gmail a few years ago, same account.