What makes adult content "degeneracy"?
It's decoupling what shouldn't be decoupled in order to optimize what shouldn't be optimized.
Rather like how your employer's janitors are from a service company, your uber driver is an independent contractor or whatever, your mortgage has probably been resold like five times, etc.
All examples of having more complex interactions stripped out.
People can do stuff for fun, because it feels good, or for whatever reason. Not everything in someone's life has to be done for a direct survival goal. People go for runs because they want to be fit or achieve personal goals, (probably) not because they want to be better at outrunning a boar that they're hunting.