After reading some HTMX criticism, there's one point people seem to miss. Making HTML your application interface does *not* prevent you from having a JSON (or something else) API. If anything, it probably forces you to split your functions better. e.g:

  def get_user_data(user_id: int) -> Dict (JSON-looking data):
      ...

  def render_user_view(user_id: int) -> HTML:
      user_data = get_user_data(user_id)
      render_template("user_detail_view.html", context=user_data)

If you need the user data in a JSON API, nothing prevents you from exposing `get_user_data` as a JSON endpoint. You can also use WebViews in a mobile app.

People tend to overestimate the "interactivity" needs of their apps and underestimate what they can achieve by just swapping HTML. HTMX also lets you swap "Out of Band" [0]. This makes it easy to model more complex interactions (like "reactions"), for example, updating a counter somewhere else in the app when a form is submitted. Reactive frameworks can also become a Rube Goldberg machine if an app is not properly designed from the beginning. Then you start fighting rendering loops, build dependencies, components' side effects, etc.

Personally speaking, HTML-driven apps are not just about easy vs. hard development, it's also about your users [1]. Maybe a big React app runs fine on 8 CPU cores and 32 GB of RAM, but very often, your users just want to read some content, maybe submit a few forms, and leave. They may not want to download 2 MB of JS so that the page can render boxes with text, even more if your browser can already do that if you give it some HTML.

[0] https://htmx.org/attributes/hx-swap-oob/ [1] https://shkspr.mobi/blog/2021/01/the-unreasonable-effectiven...