I've had 3 cars with this type of cruise control, 2 Teslas and a BMW, and I've done a lot of miles in all of them (20k+ miles in each).
The BMW has never phantom braked.
The first Tesla with Mobileye/AP1 has never phantom braked.
The second tesla with Teslas hardware and latest software phantom brakes, albeit not very often.
I'm sure it has happened and can happen to any car, but in my personal experience the odds do point to an issue with the Tesla home brew implementation. It's possible its trying to be too clever to be honest, looking for ghosts that aren't there like shadows under bridges and lorrys out to get you. The other systems may well be simple in comparison, and at the limit of what they can do, but they work.
Another hunch is Tesla got a lot worse after the Joshua Brown decapitation as the car didn't see the lorry and while it was a 100% misuse of the system, it's still bad press for Tesla. All AI models require a balancing of false negatives and false positives - reduce the chances of a false negative (there is an obstruction but you don't see it) will result in an increase in false positives (there is no obstruction but you think there is). The hunch is tesla moved the dial to reduce false negatives but in doing so increased false positives ie phantom braking.
The other aspect of this is time of year and weather can play a massive part. It's fairly logical that the system is responding to what it sees and shadows, contrast, lens flare, brightness etc which all vary significantly over the year will result in different responses. Plus, if the speed is being set by the vehicle in front rather than an open road in front it could result in very different outcomes (the car is looking at other clues to how fast it can go). Maybe the settings make a difference too for some reason, a different set of rules in the car.
The point I guess is you can drive the same bit of road and get different results depending on a bunch of external factors, drive in traffic might be better (or worse) than driving on an open road, driving at 7AM might be different to 10AM as the sun is higher in the sky etc.