I'm not sure what I would do if I lived in a city
where electronic transactions are a requirement for
public transport.
Step into my office ;) There are many things you can do, walking is the best one. You can pay for Metrocards in NYC with cash though. The machines still accept them.
I'm not sure what I would do if I lived in a city where electronic transactions are a requirement for public transport. I guess I would walk as much as possible... or even move to an alternative place.