htmx does not require many more round trips to the server, front end scripting is perfectly compatible with htmx:

https://hypermedia.systems/client-side-scripting/

in addition to native html features like <details>, etc.

htmx can often decrease the number of trips to a server because in the hypermedia model you are encouraged to deliver all the content for a UI in one fell swoop, rather than in a series of chatty JSON requests that may be made due to opaque reactive hooks.