I wrote an essay on that topic here:

https://htmx.org/essays/when-to-use-hypermedia/

Things that involve a lot of events that need to be handled quickly are not a good fit for hypermedia. Sometimes you can have a rich island inside hypermedia though (e.g. a rich text editor w/ autocomplete, etc) so long at is triggers events and offers form participation. Two common examples I give are google maps and google sheets. Those would be difficult to do well in htmx. (But the settings pages for them might be a good use case for it)