Deleting lib/linux-x86_64/lib in the game directory fixes it.
Cheers, this worked! It still doesn't launch on Linux with the current build (Jun 19, 2021) unless you delete the included Python libraries.
I do wonder what's going on here, though. My guess is the included libraries are old or missing components, so when it's deleted, Ren'Py uses the Python libraries present on the user's computer, which are newer and more complete.