I think it is important to think about kids’ ability to support themselves over the long term rather than the short term. If having a job interferes with academic success, then I discourage my kids from working. If an unpaid internship helps with future jobs, then I would support my kids entirely during that time. And so on.
The other factor might be health challenges- medical or psychiatric- that make it harder for kids to work and study at the same time. I have a kid in her late 20’s and am still helping her substantially.