I remember, working with a co-worker, we planned out the process (a step-by-step on the application like this post) and it made sense to me - but this journey was much harder for my co-worker.
Why is this? Simply because he is familiar with MVC pattern of sending json data back and forth, and getting the frontend to update and render it, etc. The idea of html flying with htmx as the behaviour (inside html tags) was just too much.
For me, I always preferred the old school way of just letting the server-side generate the html. All htmx does is adds extra functionality.
I tried hard to explain that we are sending html back, and to break things down one at a time but each new task was left scratching his head.
In the end, our website had somewhere around 20-50 lines of javascript! Much smaller footprint than over 400 lines in our previous project (that being generous). Sure, our server side code was larger, but it was all organised into View/PartalView files. To me, it made really good sense.
In the end, I dont think I won htmx over with my co-worker. As for another co-worker, who had a chance to build a new project with htmx, decided on some client javascript tool instead. I dont think I got a legit answer why he did that.
With all this above, I learned that some (perhaps most... perhaps all) struggle to adapt to htmx based on their many years building websites a particular way, with popular tools and javascript libraries. Overall htmx does not really change anything - you are still building a website. If anything htmx just add an additional layer to have website really work.
Yoda's words now have new meaning :- "No! No different. Only different in your mind. You must unlearn what you have learned."
For some its just not happening. I guess Luke Skywalker really shows his willpower, being able to adapt to htmx easier than others. :-)