"Extremely supply-limited cities" could just mean outliers like NYC or SF, or it could mean literally every city in the country, depending on your definition. And by definition, isn't it impossible to have an extremely supply-limited city with very little barrier to home ownership?
How much of salary - CoL can an average person dedicate to building capital?
I'm not saying it's hopeless, only that there are systemic factors fighting against home ownership in extremely supply-limited cities.