Well, the problem is… they did: https://developer.arm.com/Architectures/Unified Extensible Firmware Interface
But then came along the Pi guys that should’ve implemented an UEFI to push the market into that direction but never did.
The new Snapdragon X machines actually seem to have UEFIs: https://www.youtube.com/watch?v=m-Damzgq5Bg&t=978s&pp=2AHSB5ACAQ%3D%3D
But we need more, tablets with open boot and drivers are important.
Some people can’t because they need updated proofing tools and that version no longer has updates.