"I find it odd that a piece of glass is a dealbreaker."
I've been driving 49 years and have replaced 5 windshields, all broken by trucks throwing rocks. In some cases, my insurance covered a new one, in some cases, I paid most of the cost - upwards of $1000. None of those were a fifth the size of the glass top that has been shown. I suspect replacing the top will be so expensive that a 5-yo Model 3 with cracked glass would just be totaled by an insurance company. At the very least, I can't imagine getting the work done anywhere other than the factory or a very specialized glass shop, because speaking from experience again, the people that typical auto glass shop employs would not be able to do the job.
I might add, I keep vehicles a long time. In those 49 years, I've only owned 6 cars and two motorcycles.