We do have ARM CI pipelines now, but I can only imagine what a nightmare they would have been to set up without any ability to locally debug bits that were broken for architectural reasons.
Native is also much faster than qemu emulation - I have a personal (non-.NET) project where I moved the CI from docker/qemu for x86+arm builds to separate x86+arm runners, and it cut the runtime from 10 minutes in total to 2 minutes per runner.