If you price people out of the trains so they start driving cars again or even taking busses you are suddenly losing a huge amount of volumetric efficiency in your transit system.
Optimal cities can get almost everyone anywhere either walking, biking, or riding train all the time. Any requirement for road bound vehicles is an infrastructure failure of city planning. There are exceptional circumstances (moving heavy items that can't be carried) but they should be just that - exceptional, and rare.
Discouraging people from working where they live is the worst inefficiency you can create.
I used to travel, in Philadelphia, from a Main Line-adjacent community, on a bus to 69th Street Station, and then on the Market-Frankford Line, and then switched to the Broad Street line, all the way up to Temple U. for a $10/hr job, on a $1.30 token plus a $.60 transfer, each way. That's outrageous. I was mooching off the system, and my employer was mooching off the system as well. If they made me pay higher fares, well, I could afford it. What's an extra $3.80 when you're making $10/hr? At that wage, it was a small fraction of the time spent commuting.