My guess: The kids who used Discord for gaming grew up, and just went with the familiar thing when starting new communities and projects.
Also, Discord did heavy marketing early on, until it carved out a network effect. So here we are.
GE-Proton8-28 Released
Lutris Release v0.5.15
AMD Publishes FSR 3 Source Code
FFmpeg Lands CLI Multi-Threading As Its "Most Complex Refactoring" In Decades
Feral's GameMode 1.8 Adds CPU Core Pinning and Parking
Workaround for broken Battle.net update 14542
vkd3d-proton 2.11 Released
Mesa Radeon Vulkan Driver "RADV" Works Around Bugs For Unreal Engine
Wine-GE-Custom breaks wine prefixes when enabling Emulate Virtual Desktop
TuxClocker 1.3 Preparing Additional AMD GPU Voltage & Memory Controls
The LXQt team announces the release of LXQt 1.4.0, the Lightweight Qt Desktop Environment
Trying Out & Benchmarking Bcachefs On Linux 6.7
Bcachefs Merged Into The Linux 6.7 Kernel
Fwupd 1.9.6 Brings Linux Firmware Updating For AMD Graphics Cards
Intel Comes Up With A Way For Vulkan Sparse Support On Their Existing Linux Driver
An Audacious Plan to Halt the Internet's Enshittification - Cory Doctorow (DEF CON 31)
PostgreSQL 16 Released
DXVK 2.3 released
Mesa Adds GPUVis Integration - GPU Trace Visualizer
Casefolding For Bcachefs File-System Posted
That's most likely due to low rankings. Lemmy doesn't prevent it.