[dredmorbius]

Note that you've made the leap from "may be" to "must be".

There are numerous highly persistent behaviors, including play, entertainment, sleep, drugs consumption, recreational physical activity in excess of all training response stimulus requirements, etc., which nonetheless continue.

While I'm not certain that all are beneficial, and I have a difficult time myself accepting certain of these, I suspect they play a useful and possibly even vital psychological role for those undertaking them.

Even explaining these as coping mechanisms for underlying pathologies isn't particularly satisfying.