Arm booting is unfortunately still a mess, but at least for server-class machines there's been some adoption of SBSA/SBBR (https://en.wikipedia.org/wiki/Server_Base_System_Architectur...). Of course server-class machines are not the same as the cheap tat that everyone buys. You can install SBSA/SBBR-compliant firmware for your Raspberry Pi 4 (https://github.com/pftf) but it's not the default.