AFAIK some automakers also cut down on the number of sensors by doing stuff like reading the already implemented sensor(s) for the ABS to provide the tire pressure warning function.
Eh, you really don't want a car without ABS, though. For motorcycles, I kinda get it since you can't do some stunts with ABS, but on a car, it has zero benefit nowadays. Mandatory ABS, seatbelts and airbags would be the big things for me, followed by sexy, modern ESP, TC for powerful RWD cars and collision warning beeper (no autobrake at high speed, that shit's deadly and I hate that it can't be permanently disabled separate to the beeper).
It’s required because it’s a safety issue. I think that’s the intent behind almost all mandatory sensors. That’s why the post put “useless” in quotes. I’m highlighting just that it may be required because it’s needed for safety.
However, many motorcycles have ABS as optional equipment and many people (non-stunters) don’t opt in for it. Meaning, many people don’t recognize (or don’t care enough to pay) the safety aspect.
I never thought about ABS while purchasing my little 250cc Kawasaki Ninja about 20 years ago, but in retrospect, I wish I had it! Skidding isn’t as bad for vehicles with 3+ wheels; they stay upright, at least. It had rained earlier that evening, and for whatever reason (skill, pavement change, oily film on the road surface, etc) when I braked before a turn the back-end slipped out from under me. Luckily, I walked away with just a sprained shoulder, broken thumb, and a spot on my kneecap worn down to the bone.
I thankfully was wearing riding gloves, helmet, and boots; the pavement wore through several layers of the leather, my hands would have been shredded like my knee, or worse.
Using ABS sensors to justify new regulation is a circular argument if those ABS sensors were installed because of regulation. I was arguing otherwise, that ABS would be installed in a big majority of cars no matter what, and that gives a non-circular argument.
Looking up some data, it was about 75% of cars and rising in 2007, so not as high as I expected but still pretty high. There's some circularity but I'd say it's mostly not circular.