Yes, you are right. My response was based on the presentation from the first page: "htmx allows you to access AJAX, WebSockets and Server Sent Events directly in HTML, using attributes". In the meantime I read the documentation and, as you just said, it supports animations and much more.
htmx supports animations too, and it has extensions to add further functionality. Of course those projects differ in their functional range, but they share the way they work; by adding attributes to HTML.