You are drunk after a late night. Some sort of public transport will bring you home. You want to do some hiking today? You just go to the nearest train station and decide at the last minute. You want to go to that music festival/concert on the other side of the country? Take the train, have a nap, chitchat or share a meal with your friend for a few hours without the stress of traffic, looking or paying for parking a car at your destination. Train is great, it allows you to move from A to B while basically being at the pub.
You might not need to access your whole country but once you realize you can you use that opportunity and realize your country is much deeper and more interesting than you thought it was.
[1] https://www.sbb.ch/en/timetable/mobile-apps/sbb-mobile/easyr...
Mostly, but not necessarily, within regional transportation networks.
As a for example: I pay roughly $1200 for one year of travel within the city of Zurich and the adjacent zone including the airport.
This includes any mode of transportation, except taxis.
A Generalabonnement makes more sense, though, commuting from, say, Zurich to Basel, which is not uncommon.
Edited to add: Regional commuter passes also allow for use of intercity trains, provided that they stop within your zone of validity.
There are yearly abos for specific routes (home to office, typically) that you can choose for 1/2/3/4/5 days a week. But the price usually gets close enough to a full GA that most people in this situation opt for a GA. And many employers cover the 1/2 fare card or GA for their employees.
SBB also (used to?) has a plan where you get a yearly GA and a Tesla or eGolf in every major train station you arrive. It feels magical: get on any train any time and when you arrive there is a car waiting for you. Use it, get back on the train, and there is another car at your destination for you to drive. It isn’t cheap but it’s a pretty neat concept.