I completely without knowledge on the topic would imagine the "for fun" aspect is probably a pretty dominant factor.
I play disc golf pretty regularly. Over the last 10 years, it has exploded in popularity.
I'm not sure that the explosion of popularity has resulted in better people performing in tournaments.
But what has changed, is how much money can be won by competing in disc golf, and how much money is available across the sport as a whole.
The increased prize money has dramatically changed the number of people and level of competition for people playing the game seriously as well as how seriously everyone involved in top level play takes the sport. This then has a trickle down effect in the number of people and seriousness of things like training clinics, professional teachers, professional and more intelligent course construction and analysis. It pays for more analysis into all aspects of gameplay to increase the competitive edge of performers at the top.
The increased player base, in turn, pays for most of this, as it increases the potential market for the same services as all of the above. And the more seriously top level play is, and the higher the winning prize pool money goes, the more respectable the sport has become in the public eye, which in turn creates a catch-22 effect whereby players appear more willing to spend more money on the sport on those services.
All of which increases the level of play at the top. And you can see it in the quality of new young athletes that are coming up in this new environment, and how much better they are and how much more they are able to learn from the more widely accessible resources than their equivalent counter-parts were 10 years ago.
Its been fascinating to watch, and very exciting. Particularly over the pandemic, the sport has come from being called "frolf" on a golf course or in your local park, to "disc golf" with multi-million dollar professional contracts, dedicated disc golf resorts and private courses, training clinics, and dedicated PPV channels. Very cool : D
A counter-example might be the various competitive communities around different forms of boardgames, which tend to be very small, but often very competitively driven and taken very seriously by a very dedicated community, but I don't know enough about the topic to discuss : )