well, GHA supports running actions in containers, which is the best way to control the environment your CI/CD runs in, so putting your runner in a container won't work for everyone.

but, if it does work for someone, doing what you've done will give a much better experience to their developers.

my employer uses single-user VMs for it's runners; it works well, but sometimes actions invocation is high and it can take a few minutes for a runner to come around to taking my job. that would be much less of a problem with dockerized runners.