maybe i know more linux people here that'd know how to help:
I've noticed that emoji are completely invisible, anywhere (except Discord, which I assume does its own thing entirely). No matter whether I try to paste one myself (from e.g. Emojipedia) or read messages containing them, they just cannot be seen, not even with the "tofu" block. I'm running Linux Mint 22.3 with Cinnamon.
fonts-noto-color-emoji and fonts-emojione are both installed through apt.
@wildweasel Looks good, I had that same problem and my locale was set to C. Setting it to any utf8 fixed it for me. 
@corrupt well, the problem has already been addressed by uninstalling fonts-noto-color-emoji (a different set is installed instead now), but here's that output in case it still helps