If I understand correctly, what this project does is take the actual postgresql sources, which are written in C, compile them to wasm and provide typescript wrappers. So you need the wasm to be able to use the C code from js/ts.

WASM means you only need to develop for one target run time. That's my guess as to why.

Yeah... I was super excited by this project when it was first announced--and would even use it from Wasm--but since it ONLY works in Wasm, that seemed way too niche.