The wiki tells you what you need on arch, and what you need it for. Those packages also don’t seem to have kernel-specific or dkms versions, so seems like they’re not kernel modules.
Mind you, the setup is clearly not monolithic, with different components for different purposes, including alternative options. On top of that, each distro will make different choices - Arch provides the components as packages and puts the responsibility of installing the right ones on you. Some features might be built into kernel drivers, like working video output, but Vulkan support clearly wants a dedicated driver.
I think it’s only for the EU, and the other browsers don’t have a solution ready - porting their engines for iOS is a lot of work, which takes time, and might not even be worth it when they still need to maintain the safari-based version for the rest of the world.