A vast, vast array of features. Multiple new renderers, material systems (lumping node systems into this), 2D animation systems (mostly via grease pencil AIUI), video compositing features, sculpting (I think is new since then?)
I mean, even if you aren't using it now, it's probably worth looking at e.g. the latest release notes https://www.blender.org/download/releases/4-3/ just to see the array of things improving and adding onto stuff that mostly didn't exist 12 years ago.
I mean, even if you aren't using it now, it's probably worth looking at e.g. the latest release notes https://www.blender.org/download/releases/4-3/ just to see the array of things improving and adding onto stuff that mostly didn't exist 12 years ago.