I'd add that it wouldn't be so outlandish to assume that any superficially and widely agreeable movement might just be astroturfing, considering how cheap and easy it is to persuade people in general, but also specifically by making them think everyone else feels the same, and how often the arguments just parrot whatever the various internet personalities happen to be saying about it without any additional insight.

It is generally not a huge difference in small systems like you find in college towns.

It is a pretty substantial portion of most major transit agency budgets; BART for example has a farebox recovery of about a third. If you were to totally make it free you would need to basically increase the other sources of funding by 50%.

LA metro fairbox recovery is like 5% fwiw. Look up median income levels too on that system and you might be inclined to slash fares.

the argument has always been, is it better to spend that 5% on making it free, or is it better to spend that on making services more useful so that people actually switch to it?

The cost is not really the reason LA Metro ridership is so low and farebox recovery is so low.