I think, both FF and chromium on Linux disable WebGPU by default. Of course, it depends on where exactly did you get it (what kind of default settings people that packaged it for your distro used).

Just look up "<browser name> enable webgpu" in you favorite search system or ask an LLM chatbot "How to enable WebGPU in <browser name>?", follow the instructions and it should work just fine.

Check navigator.gpu in the console on the Linux machine. If it is undefined, that is your answer, and it explains the silence: the page has no API to fail against, so nothing throws.

WebGPU on Linux is still the exception, not the rule. Firefox ships it enabled by default in Nightly only, not Stable or Beta, with Linux expected during 2026. Chrome enables it by default on Linux only for Intel Gen12+ (from 144) and NVIDIA with driver 535.183.01+ on Wayland (from 147); everything else is behind flags, roughly --enable-unsafe-webgpu --ozone-platform=x11 --use-angle=vulkan --enable-features=Vulkan,VulkanFromANGLE. Distro Chromium builds also differ from Google Chrome here more often than people expect.

Which matches what you saw exactly: works on iOS, black text on both Linux browsers, clean console. Worth the demo printing a one-line "WebGPU unavailable" instead of rendering black on black, because right now a missing API and a broken shader look identical from the outside.