PyScript is built on top of Pyodide! But it's probably the first well-supported way to build frontend apps with it. I imagine the fact that Anaconda is backing PyScript means that there will be increased investment into Pyodide as well.

AFAIK, this is the first time that CPython could be directly compiled for WASM (with no patches IIRC), and PyScript adds a number of components for better integrating Python with the DOM, importing extra modules at runtime, as well as a dedicated py-script HTML tag.

But I've personally never used either, so maybe I'm missing something too?