I wish Canon had a facetracking feature that could be used while looking through the viewfinder. AFAIK that is not possible with any Canon FF camera, right? Focus peaking while looking through the viewfinder is also something I would love to have. Tell me that is not useful?
Your statements boil down to: All technological advancements in other cameras are just marketing. That is a very cheap shot, which is why I do not consider your oppinion valid at all. Differentiate at the very least.
Have you ever used the iTR tracking feature offered by the 1D X, 1D X Mark II, 5D Mark IV, and 7D Mark II? Three of those four are FF cameras.
When using AI Servo AF with iTR active, if one initially acquires AF on a face, the camera will use information from the RGB+IR metering sensor to assist the AF system in tracking that face using the color/shape of the face. If some of the many other user selectable AF settings are properly chosen, it does so fairly well and with decent speed. The only reason we probably don't hear more about it is because:
1) It's not perfect, particularly if some of the other user selectable AF parameters aren't set for speed. Canon doesn't tout something that only works as advertised some of the time the way Sony does.
2) Too many pro shooters don't bother reading the 500+ page User Manual or the supplementary 200+ page AF Manual when they get a new 1D X Mark II and don't even know iTR tracking exists.
3) It requires using 'Auto AF point selection' and the users who even get that far immediately dismiss it because they don't read the manual to discover that even when in 'Auto AF point selection' AF mode the initial AF point each time AF is initialized can be a manually selected single AF point.
4) Many shooters select one (of six available) AF cases and stick with it forever. Each AF case has three parameters that are adjustable within that case. It takes a long time and a lot of experimentation to to learn how to use the various use cases most effectively for the various scenarios for which they are designed to be used. That means shooting in non-mission critical situations (a/k/a "practicing") to learn how to use it. Too many pros think they don't ever need to practice shooting with a new tool when they're off the clock. Imagine a classical musician that gets a new instrument or is asked to play a difficult piece they've never done before thinking they don't need to rehearse before the premiere.