SCSS seems like it gets out of control after a while though without rigor from the developers. The last app I worked on had a half-assed SCSS approach that started off with a decent base, and then got tacked onto with a ton of ad-hoc styles that weren't nested where they "belonged." Inconsistent usage of paddings/margins everywhere. It was a mess.
At some level, this is unavoidable and just something to get used to. But those longer selectors can be mitigated somewhat with a sane CSS methodology. One of the benefits of CSS is that there are 100 different ways to achieve the same result—and I personally wouldn't trade that for a more opinionated CSS spec.