While many LEGO pricing decisions are egregious, this one is surprisingly fair. Build quality is also much better. Looks more like what it's supposed to be, colors are more uniform, and the treasure chest isn't just a brown crate
Most LEGO elements are ABS, not polypropylene. According to this article, PP is used mostly for parts that require some flexibility, like living hinges:
https://bricknerd.com/home/every-type-of-plastic-used-by-lego-2026-edition-3-12-26