I wouldn't call the banner huge, at least not in the examples I've found at [1]. The cookie banner doesn't look out of the ordinary and hides when you start scrolling.
They may have changed the screenshots but I confirm that I received the same kind of email. Same technique and email from Google, the only difference was that it had some spam at the bottom of the email.
If I received an email from google with text formatted like this. I would automatically have doubts it's anythig genuine.
While Gmail isn't anything to boast about UI wise. Google often have good enough an consistent UI patterns where this screenshot looks like there was no thought put into it past slapping a google logo on top.
[1]: https://www.reddit.com/r/GoogleSites/comments/1ffz1a5/google... ; see websites like https://www.woofiepie.me/ https://www.manuelfally.com/home https://www.wedding-whisperer.com/