> But society in general does not really support professional athletes in any directed “conservatory” sense, beyond the weird obsession with college sports in the USA.

At least some countries have programs where (candidate) Olympians get professional support and a stipend.

See for example https://www.uksport.gov.uk/our-work/investing-in-sport/how-u..., https://www.dosb.de/en/themen/athletes/services-for-athletes

A country like Spain has a formal system of grants and awards for athletes designated as "elite" and supports them roughly at the same pay as it supports junior university professors.