Tesla is not miles ahead of auto makers that came before them. They do not have better build quality, higher durability, higher ownership satisfaction, are not more affordable, are not safer. Other automakers could easily transition into that market and make better vehicles than Tesla if they had the incentive to.
Their battery and charging technology is impressive and their supercharger network gives them a moat, but not enough of a moat. A concerted federal effort would quickly erase it, and that not happening yet is mostly down to incentives.
Legacy carmakers still do things by model year. Their processes are waterfall in a world that's gone agile. As far as how well their metal box protects you when you're sitting in it and you get into a crash, all of their models rate very high. There's are fit and finish issues, you're absolutely right, but the dinosaurs aren't evolving with the times. We live in a software driven world now, and their old processes haven't been torn down and built from scratch to meet that reality. As a consumer, the new F150 Lightning does have a lot of cool features, so there's hope for them yet, plus Ford CEO Jim Farley's been driving around a Xiaomi SU7 from China. We'll see if he can light some fires under some asses and manage to turn the Titanic in time.