A right-click/View Source would allow you to reevaluate your initial impression due to the presence of elements introduced in HTML5 (released in 2008).
The fact that you can do that and not stare at a soup of minimized Javascript tells you a lot about htmx.
Why in the world would I want to split a team in two highly coupled halves that can't deliver any value by themselves? Division of labor? Seriously? Are we back to the 18th century?
My hunch is that in the first picture there was at least one person inside each car and they seemed to be going to work. In the second picture, there are a lot less people and they are definitely not going to work. Are they getting rid of people and jobs?
For me, it clicked immediately. It is a simple way to partial updates of the UI, without having to worry about a ton of tooling. It also pushes most of the logic to the backend, which is nice. It also constrains some of the UX decisions, leaving less room for useless craziness.
htmx is pretty agnostic with regard to the backend side of things. You can use anything you want, really. There are htmx extensions to Django and I am working on a similar one for Express. Basically, a very simple middleware to deal with custom request and response headers.