The thing is, because it's numbers-first, it's -- theoretically, anyway -- much more easily extensible than those games with thinner, less detailed, but just-as-expensive books.

And that's just if you care about balance. Sometimes you just don't. The game's core audience to this point has very much seen the strict balancing as the core identity of the game -- and it is a core feature, with how it ties into the four degrees of success system (the true core of the game, as far as I'm concerned), but there's so much good Pathfinder content out there that one shouldn't need to worship at the alter of Thanos to be interested in the game.

The bestiary is kind of amazing, and is worth the cost of admission all by itself. The Monster Core has some really compelling creature changes, too. And the creature creation space is incredibly inspired. The Battlezoo bestiaries are so far above and beyond anything I've acquired for 5e, I don't even know how to speak to it.

If anyone wants to join in on that, they basically have to do it in secret because trying to create content for the game in public and seeking feedback turns into a recreation of the "never again" meme.

We learn through trying and failing, and there's currently no room for failure in the largest community for the game.