Is the prevailing advice still not to bother with self-hosting email?

Unfortunately, yes. Here’s a fantastic blog post from someone who gave up on self-hosting last year due to the vast number of problems with self-hosting. The post also does a great job at pointing out why the death of self-hosting email is so bad in general, but still regrettably concludes that it isn’t worth it in any scenario right now.

They’re not, they’ve had the bZ4X for over around a year now. It’s kinda mediocre but certainly not the worst BEV I’ve seen.

Any idea why Tesla went against that to a shatter proof glass?

Because Elon Musk is a manchild who thought it was cool and forced his engineers to entertain his idea? The entire design of the Cybertruck just screams “someone high up had a shitty idea and told engineering they had a month to figure out how to make it real without any regard for rules or regulations”.