Like, when demand goes straight up and supply can't go nearly as fast, what else would anyone expect? I don't understand why everyone always acts so shocked that the completely predictable happens over and over.
Seattle has actually been much better about allowing more housing than some peer cities, like SF. But compared to cities in most other developed countries, the situation is still awful. For example, the kind of very low density zoning that is commonplace in Seattle literally doesn't exist anywhere in Japan or Germany.
I don't think you'll find many urbanists or YIMBYs pushing to demolish greenspace like parks or trails. I'm certainly not; if anything, I'd prefer to push to acquire more greenspace, perhaps by redeveloping surface parking lots. As for housing needs, there's plenty of space where things are already developed.