Do you have any big box retail nearby - super center, grocery or home improvement? My kids and their friends had good luck finding summer jobs at these place after graduation from HS. Some even offer educational leave so college kids can work during school breaks and subsequent summers without onboarding.
I think being 18 and being available to start working before high school kids are out for the summer probably increases your S23’s of being able to find something versus when he was applying as a minor high school student.