I just checked wikipedia and there is a paucity of info showing actual effectiveness, and some showing what I just mentioned. It's a little suspicious that there is not overwhelmingly positive data https://en.wikipedia.org/wiki/Anti-lock_braking_system#Effec...
1. If you are too fast to squeeze the brake lever, the tire carcass will not deform properly, giving you the the maximum braking potential. There's a large difference in braking performance just grabbing vs. applying in a controlled manner. You can look up motorcycling racing brake application for more info on this.
2. Breaking too hard can cause a stoppie (a wheelie using your front wheel). Done improperly, that creates a lot of fear in the rider.
3.If you lock the brakes and steer, you are likely to have the front end of the motorcycle dip, causing it to lowside.
ABS helps mitigate all 3 of these issues.
ESC in a car for me can be helpful or detrimental depending on the vehicle and the implementation.
I have an old 90's tachoma that doesn't even have antilock brakes. It drives a bit like a car when compared with a modern truck, but the rear will slide out even on gentle curves, in the rain it can slide hundreds of feet when stopping (yah pulse the breaks manually), and its narrow and high meaning they roll over if you look at it wrong. One doesn't feel "safe" in it, and you know to maintain a lot of stopping distance, slow down before curves, and generally drive like a 90 year old. I have a much newer tundra. It is a brick on wheels with magic traction control, and it feels glued to the road because of it. Except it is easy to fail to respect it and discover one is simply going too fast into a turn, or a stoplight/whatever, and the antilock and traction control aren't going to save you. The one significant advantage is that you can steer it into a ditch while panicking rather than ramming it straight into oncoming traffic when that happens.
So, i'm betting in the end, the more aggressive driving the turndra encourages by giving people more of a feeling of being in control negates some of the additional safety. It's like power steering lets tiny women (and men) drive massive trucks/SUVs they wouldn't otherwise drive if they had to crank those huge tires holding all that weight manually.
https://en.wikipedia.org/wiki/Electronic_stability_control:
Not "the most important since seat belts", not "the most important since air bags", not "the most important current advance". Electronic stability control is THE most important safety feature in modern automotive vehicles, the single biggest factor in whether you will die because you got in a car _period_, more than air bags, more than seat belts, more than crumple zones, more than _headlights_ or _tire compounds_ or _safety glass_. Preventing an accident entirely is better than any mitigation and ESC is incredibly good at preventing a huge class of accidents.And those numbers are from 2005-ish. Modern active rollover prevention and traction control systems and anti-understeer/oversteer controls are _even better_.