All those things would be solved by sending text email. Whereas this overly complicated markup langage to HTML w/ javascript, and server response dynamic stack of programs will fail completely if JS doesn't execute just right in the mail client or there's some connection issue.
I guess for for-profit contexts one cares more about aesthetics than functionality.
The HackerNews thread about [0] has much discussion on this topic.
[0] https://useplaintext.email/ ( Thread: https://news.ycombinator.com/item?id=32810515 )
[1] https://drewdevault.com/2016/04/11/Please-use-text-plain-for...
The javascript is basically only used for templating, defining reusable components and rendering the static HTML together with inline CSS which does make a lot of sense because writing „bulletproof“ email components that work on every client is a huge amount of work and you would generally like to keep the amount doing that to a minimum.
In my experience every company uses some type of email templating system, some off the shelf, some built in-house, I actually got my start in (actual) programming by building one for my team.