It looks pretty bad on Linux too. Somehow they managed to transport the crappy font rendering from Windows to Linux. It really feels like it's not built for Linux, but just shoe-horned in.
Edit: And also note that, for whatever reason, GNOME does its own thing where you also have to edit the GSettings in addition to the fonts.conf settings depending on what app you're running.
Do you also criticize Chromium's font rendering? Maybe you are just looking for things to complain about?
However on Linux it does, so this sounds like a broken fontconfig setup, or a toolkit not getting the right hinting config.
It's a years old Chrome bug. Wish they had a Chakra version of Elektron.
I always use 15pt Fira Code