I hire freelancers frequently. I never ask them what their age is, I ask for their portfolio and what they are skilled in. Maybe you should look into contracting.
That said, this also works for permanent jobs, so if you're struggling to find those then maybe you are out of luck.
That's honestly the question when it comes to this type of thing, there are so many different skillsets and not everyone can find contracts as easily as they'd hope; or it's not as reliable as they need for their life.