The run script provided by the hostapd-runit package just crashes, because it tries to run hostapd with a -s flag that apparently is no longer supported by the current version of hostapd (2.10-1). Simply removing the -s option from the run script fixes the problem. I guess another possibility would be to give the -B option, but I didn't test that. I cannot log in to gitea.artixlinux.org, so I cannot submit this as an issue or pull-request there.
I think it's supposed to be "-S" (capital letter).
Fixed the flag to use capital S and added a log service as well.
It can't run in background it would make the service infinitely restart