IF ABS engages, your total braking distance can get huge. But, there are numerous reasons that might happen. As discussed, crud on the road that could include the diesel mentioned, but also oil, water, sand, gravel, snow, ice, etc. How new the tires are also makes a difference. The rubber is constantly getting harder as it ages, which lengthens the stopping distance and diminishes the grip. As mentioned, it's not the narrow tires as the contact patch is the same, and actually should be better than a shorter, wider tire...it is oriented along the typical direction of travel verses across it. But, if there's crud on the road, in that narrower path, length doesn't help.
Personally, I've found the braking response to be quite good. Some people drive with two feet, and it's my opinion that most people end up riding the brake at least part of the time when they do that...it's REALLY hard to hover over that pedal long-term. This can overheat things, and can glaze the rotors, which can also affect the braking distance and the longevity of the pads and rotors.
2014 i3 BEV, 2021 X5 45e
(The i3 will be sold soon, <17K-miles, interested?)