It's hard to say. Of course the OEM should care what their dealers do and how they treat customers, but ultimately the dealers decide how they are going to handle things.
I haven't had any failures on any of our Mazdas so far (2013 CX-5, though only had it for 2 years. I change cars like clothes, 2014 CX-5 - spouse had for ~70k / 6 years, 2015 Mazda 3 - had for 27k / 6 years). Only issue I had was a battery that died during the pandemic, and it didn't really die - I was able to nurse it back to health and then it kept working through when I sold the car 3 years later. All that to say, I haven't been able to test our dealership with a major failure. But the buying experience did exceed what we experienced at the other dealerships we visited (Hyundai, Chevrolet - lots of unwanted sales contact and in person pressure.)
Honestly it could have been something as simple as a a missed bleed of an air bubble in the brake lines. But this was on a less than 3 yr old car, and its been a while since we last discussed it, & I don't recall if they had any sort of brake service where that would be a possibility - either way after a scare like that, one expects your car maintainer (in this case the dealer) to be open to a bit of diagnostic work - even if only to maintain good relations for future purchases.
I haven't had any failures on any of our Mazdas so far (2013 CX-5, though only had it for 2 years. I change cars like clothes, 2014 CX-5 - spouse had for ~70k / 6 years, 2015 Mazda 3 - had for 27k / 6 years). Only issue I had was a battery that died during the pandemic, and it didn't really die - I was able to nurse it back to health and then it kept working through when I sold the car 3 years later. All that to say, I haven't been able to test our dealership with a major failure. But the buying experience did exceed what we experienced at the other dealerships we visited (Hyundai, Chevrolet - lots of unwanted sales contact and in person pressure.)