I use flatpak Discord daily since most of those Game DEV I support used Discord and I have no problem with it at all that's why I wonder what performance-wise (and some features are buggy or just nonexistent) you talk about.
Same. Only New Games (DX12) and Anti-cheat games I really have a problem with but besides that I don't. I have over 2000 games on Steam and at least 80% of them run fine 2% I know don't and the last 18% not really played to say.
On Linux you cant stream audio or use the Krisp noise reduction thin on discord g for example. We still have issues with some games that are the key for Linux's commercial success such as League of Legends (which still has issues, especially on Intel and nVidia graphics cards), Valorant (which Is not compatible yet), Warzone etc.
We still have almost no other Native Launcher other than Steam. Launching games from Heroic sometimes Is problematic even because altough the game has a native build, Epic Games just ships Windows or Mac ones . All other launchers run fairly well through wine and forks but its not optimal.
EDIT: We also have "noob-proof" distros that are COMPLETELY BROKEN. Ubuntu, for example, might kill your graphical instance just by adding a PPA (It happened to me just yesterday with ppa:ernstp/mesarc). Wanna talk of all the issues Pop!_OS regarding boot and stuff? Every time I try to boot It from my main PC It says "you have to load the kernel first". People online say its an issue regarding secure boot, but secure boot Is disabled. It still has issues with the graphical store (which are getting fixed btw). Manjaro still has issues with SSL Certificates and other security concerns that make the distro completely unrecommendable.
We still have a lack of proprietary drives and peripherals software support
Linux Is at the highest point of it's existance gaming wise, but its not ready for the average gamer.