Reusable components are prerogative of the templating system, such as React, or Vue, or server side templates that the framework of your choice uses. Htmx works with already rendered HTML fragments from the back end and doesn't do templating on its own, so there's simply no room for it to "solve" reusable components

You make the reuseable components in the server templating language. It is like saying PHP, Django, Go etc does not scale

https://harcstack.org does components like this https://rakujourney.wordpress.com/2025/07/06/harc-stack-comp...

  class Counter does Component {
    has Int $.count = 0;

    method increment is controller {
        $!count++;
        self
    }

    method HTML {
        input :id("counter-$.id"),
            :name("counter"), :value($!count)
    }
  }

server-side templating languages solved this decades ago