If we are going to "pump" up the SEO factor, things like https://www.yourmechanic.com/book/#/addj=10021 for "Car is not starting" would not be in place.
Instead, maybe something like https://www.yourmechanic.com/fix/10021/car-is-not-starting
So yeah, I wouldn't necessarily hold this site up as heavily SEO optimized. Nothing against the company as they are a young company just not a good example IMO.
I'll now call out YC companies to prove my point. I went to the techcrunch demo day round 1, and have a look at http://vastrm.com/ It is a complete SEO disaster. No reasonable advisor would have said that was a good idea for an e-commerce company.
Compare their SEO strategy to a YC company that repairs iPhones, or the one that sells cars. If you don't know the urls, send me an email and I'll tell you the ones I am talking about.
The YC anti-SEO pattern exists, it is just not polite to call out SEO mistakes, because if anyone builds anything, then we must be supportive.