forces freeloading foid off bus seat

With a nominal fee (like let's say $1 in the US), nobody's going to skip out on public transit because of the cost. Well okay maybe not nobody but very, very few people, not enough to really impact capacity.

For the effect you're describing to occur, the fee needs to be high enough that the average person going from point A to point B which is served by public transit has to consider and weigh pros/cons of taking public transit versus finding other transit. That's pretty high, generally higher than most fares already.

On the flip side, making them "free" (at point of use) means you can discard all the shit around fare collection. Nobody will get held up because somebody is trying to find their transit card or it won't work or whatever. No holding buses for 5 minutes while employees go around checking tickets. Around here you need to scan your card when you get a bus for example so if 10 people are boarding a bus it takes like 2-3x as long as if they could just get on and ride.

IMO the best solution is to make them free at point of use, pay for them through taxes, and also enforce laws/rules to kick off troublemakers (who are often not paying a fare anyways). But of course the people arguing for the first point never argue for the last point.

If you're talking about public crime or something that won't happen here. But capacity is a problem yes and we probably can't sustain it at current income levels, some westoid cities do have free public transport in core areas though. Melbourne has a tram I think? Two wheelers are a really major traffic issue here, they're cheap enough to buy and operate its basically at par with bus fares but our roads were not built for more than 5% to own personal vehicles. China apparently got rid of them with their metro boom. Its still somewhat manageable but matters have gotten exponentially worse since covid, driving since has actually turned me on this question. I'll pay to not have those people driving.