This is not true, I purchased a Model 3 brand new in 2021; it has HW3 and it absolutely does phantom braking regularly on road trips. This is on US interstates.
Why do you keep driving it? I had a car that did this to me twice and got rid of it, the first time could have been a glitch but twice is simply broken and dangerous. The dealer said the car was fine.
All car brands ADAS are imperfect. If it phantom brakes you just push the accelerator, or simply don't use the ADAS.
You can drive the car normally, you aren't forced to use ADAS if you don't like it.
Yeah just gotta turn it off every single time you get in the car.
No? What are you talking about. Just like basic cruise control, you don't have to "turn it off". It just doesn't work until you don't enable.
Unfortunately on that particular car it was on by default and short of sabotaging the hardware it would stay on.