I like to think I knew what I was doing. :-)
Unfortunately, too many company admins keep saying "we don't want our customers to have to be configured correctly, we might miss a message from them" and disable all the built in protections. Hopefully the option to disable protections will go away soon.
So basically good old fashioned "quality" enterprise shitware.
I suspect the issue is that we weren't paying enough. We had maybe 10 seats. I bet if you're buying 1000 seats a bunch of Zendesk engineers turn up and configure everything for you, but with the robust email setup needing that engineering time on their side to configure... so I guess in that way it may be Enterprise shitware.