Ask HN: Why is home contracting so horrendeous?

I'm nearly seven months in to a three month home remodel. Most people I've talked to who have done remodels have similarly awful experiences with their own projects.

Contractors consistently over promise, woefully under estimate times, don't order key supplies at the right time and skirt or go over the edge of legal behavior. Yet, this is accepted as "standard practice". Why? I live in the SF bay area where the housing market is insane. Is this true elsewhere?

What experiences have others had? How have you been able (or failed) to hold a contractor to account? If things go way off the rails litigation is an option, but I'm interested in less extreme cases.