To eliminate this cheat vector, we have made the decision to prevent access to the game for Linux users. This means that Apex Legends will be unplayable immediately for those running this operating system. Playing on handhelds, such as the Steam Deck, is still possible if the user opts to install Windows.

translates to them cutting off linux support so people will be forced to use approved operating systems like Windows which will require more hardware which means more money for those companies and more intrusive anti cheat software that gives users data away

way more than just about Windows and some games

this is about locking users into approved environments with no wiggle room just like on Tron

nonSteam games, pirated games, maybe your setup or you yourself needs different settings for whatever reason, console emulation, and more

from the above link:

It is based on Valve’s version of WINE (Proton) and its modifications (Proton GE). It includes a set of scripts combined with wine-proton itself, a Steam Runtime Sniper container with the addition of ported versions of MANGOHUD (displaying useful information in the game window: FPS, FrameTime, CPU, GPU, etc.) and vkBasalt (improving graphics in games, very good in conjunction with FSR, DLSS) + many already configured optimizations for maximum performance.

One-click automatic installation (on the AUTO-install tab) of popular launchers such as: WGC, Epic Games, BattleNET, Origin, EVE Online, RockStar, Ubisoft connect, League of Legends and many others has been implemented.

For console game lovers, there are many console emulators available (under the EMULATORS tab): PPSSPP, Citra, Cemu, ePSXe, MAME and many more…

does the same thing the dwarf compressed .sh game starters do

they do what you said but with very specific instructions, settings, and tweaks you would otherwise have to manually configure

mpv without a frontend vs using celluloid as a frontend for mpv for example

Faugus Launcher is a frontend for the umu-launcher

it does not have the same performance and your fps in games will show it as well as graphics