A young person could simply argue that requiring prior experience is a form of age discrimination no different to saying "We are looking to hire someone to run

A young person could simply argue that requiring prior experience is a form of age discrimination no different to saying "We are looking to hire someone to run a project, no usage of obsolete methods allowed" and then not defining what that means. After all, "years of experience" is a rather arbitrary measure, it's easy for people to rack up years on projects and learn nothing, and it's common for young people to have insights their elders lack despite the YoE difference. See: Larry Page, Sergey Brin, Mark Zuckerberg, Bill Gates, the young Steve Jobs etc. Lots of young world-changing founders out there who easily beat people with far more experience.