SumatraPDF: https://www.sumatrapdfreader.org/free-pdf-reader

No frills, super fast and small. Been using it on Windows for years.

Thanks, I love finding little nuggets like this here.

Eh, it vendors an old version of mupdf. Very bad idea, considering that it's a C program/library handling a notoriously complex format often shared on the Internet.

Personally, I just use mupdf (which I sandbox through bubblewrap).