As a typical end user you probably won't understand what that "via" means. All you see is that your e-mail was sent "via" some unknown thing you don't recognize.
Even if you do understand - isn't the "via" specifically designed to reduce trust? "Hey, head's up, this message actually came in through this third-party"
>>> Which one looks more trustworthy? Obviously A1 looks better. B1 has a suspicious text “via way.hanami.run”.
uhh... what is the problem with gmail showing the "via ..." badge? why, as an end user, should I feel less trust in the message?