A couple of systems ago, the iOS version of the app store changed significantly. Previously, when there were available updates, opening the App store went immediately to the place where you chose which ones to update. Since that change, however, opening the App store takes you to an advertisement. You have to touch an unlabeled and meaningless icon to get to the place to choose updates. The message is clear: making a profit is more important than functionality.
This suggests that Apple made the change to Mail.app in Catalina because it was part of a plan that they thought would make them more money. They must think their customers are all teeny boppers who do nothing more profound than write fancily formatted emails about their vacations to exotic locations. Whose primary use of a computer is for the latest social media craze.
I've been using Apple computers for over 30 years. They need to learn that if it isn't broken, don't fix it.
(by the way, have you every tried to print an email in Mail.app without also printing the contents of any attachments? last I looked, it's not possible)