Why has the American hobby died, or did it?

Sense I have: people used to have *named* hobbies — woodworking, model trains, ham radio, knitting, birdwatching, amateur astronomy. These were identifiable lifestyles with stores and magazines and conventions. Now you have... "I work out" or "I cook a little." Mostly low-commitment, low-skill-ceiling, mostly individual. Is the named hobby actually dying or am I just nostalgic for something that was always rare? Boomers grew up with a particular hobby ecosystem and it had a vibe — but the actual prevalence might be similar across eras. Looking for: data on hobby participation rates over time (BLS time-use surveys?), generational comparisons, or theories about why this category of activity might have shrunk.