the goalposts were that x86 is more open source friendly than ARM. Intel and AND work on mainline Linux because they actually submit their patches to mainline and make sure that they get accepted. Sure, there's firmware, but the code to use that firmware is open source and widely used. The worst you see is maybe SoC drivers for webcams.
Compare that to ARM, where the majority of vendors dont provide source code for their kernels, and when they do boot with mainline Linux, half the shit is broken because of device trees or undocumented peripherals.
I wouldn't want to buy an ARM computer.