Implementation vs having your back
I had a 93 Lexus LS400 with traction control, at least it had the button. In WI winter it made no contribution to traction.
More recently I had a 2010 Acura TL with SH AWD (Super Handling) It was extremely competent and the dash display indicated what the system was doing when traction was exceeded.
Launching WOT straight would bark the front tires for 0.5 seconds. Launching WOT into a 90 degree turn would bark the inside tires for 0.5 seconds.
I cannot guess what it cost to develop that system, or manufacture it.
A year ago I drove a buddy's 2021 Porsche 4S AWD 3.0 twin turbo Targa @ 465hp on the TN Tail of the Dragon. It was otherworldly, as hard as I hammered it there was no sliding.
Methinks I can not engineer a system as competently as Acura or Porsche. When you get in over your head, will your DIY stability system save your butt?
jim