> gym memberships are subsidized by people who barely go to the gym and would be better served by buying day passes
In my country, they're priced in such a way that day passes never make sense. If a monthly subscription is 50 EUR, a day pass is 18 EUR. So you'd need to go less than once a week for it to be better than a Gym subscription. But at that level of gym-going, you'd never see any kind of progress, unless you do very specific training, like very heavy lifts.
So, as a rational actor you're left concluding that the only options are:
- gym membership: you can grow muscle if you go daily; you won't see much benefit if you don't. - no gym membership: you feel bad. - day passes: no muscle growth So, the middle is squished out completely and you're left either feeling bad or buying a membership. This presupposes you don't have alternatives for growing muscles, such as calisthenics, parks, free weights at home, which is the case for many. I can only conclude daily passes are for heavy gym goers that are traveling and don't want to lose progress, or other situations with people whose demand temporarily inelastic or non-repeatable.