A new Mac comes with something like 30 apps in the bar. I clicked and disabled every single one of them except Finder and used Safari to download another browser. If it was any other manufacturer, this mess would be quickly denounced by reviewers as crapware. But because it is by Apple, it is not a problem at all.
I am not expecting this to fix by itself. Maybe some major review blogs should first not parrot how magical the whole thing is and change the tone as such things are not only annoying, but also a security risk even if you don't actively use the app. I am not an expert on development for MacOS, but I would be surprised if there is no way to trigger the mail app from another app or a link. I just hope the bug is not exportable this way.