Drupal 11.3 put HTMX in core — I checked what that actually changes for AJAX callbacks

Drupal 11.3.0 bakes HTMX into core and rebuilds BigPipe on top of it, with claims of up to 71% less JavaScript and 26-33% more requests served at the same database load. I went through the release notes to see what that means for anyone who still writes #ajax callbacks, and whether Navigation is actually worth switching to yet.