[Brightcolours]

For video, big steps have been taken the last few iterations, if we only look at the dual pixel PD AF from Canon and how smooth you can AF now, and the IS (from the R3/5/6) making gimbal-less shooting better possible. Or the quick sensor readout of the Nikon Z9, making for almost no deformation during panning.

For still images, most progress has been made for making shooting easier (face/eye/monkey/motor detect, eye AF-point select, more forgiving sensors so you can totally mess up exposure settings and still get a result to post on your social media, high FPS so you don't have to time your shot, to name a few). It depends on your shooting if this progress makes upgrading a necessity.