I view PDFs on Linux with evince or xpdf. Xpdf is lighter but has fewer features.
are there any lightweight Linux terminal programs that can export PDF as plain text
pdftotext
EDIT: Xpdf probably also isn't Wayland-native, if that matters for you.
EDIT2:
https://en.wikipedia.org/wiki/Evince
https://en.wikipedia.org/wiki/Xpdf
https://en.wikipedia.org/wiki/Poppler_(software)
(pdftotext is in the poppler-utils package in Debian)
EDIT3: Oh, looks like Xpdf got ported to Qt, so it probably can do Wayland these days.