In there the issue was that other game system made it obsolete. Im pretty sure the train was used a LOT back in the early days.But on the subject of other examples of train systems that don't get any use I put forward the deeprun tram that links ironforge to stormwind in World of Warcraft, rarely used and was of use in just collecting the flight point that connected the two cities, after that everyone flew. (I think there were a cpl of quests down there but it was so empty the ERP'rs used to use it for privacy)
EDIT: Me, I am after immersion in my openworld games. I strive to make my character act in a way that would be believable. I walk whenever I can.
Regarding WoW in the above example, when I played my human rogue in wow, I used to walk to the house at the end of the cutthroat alley in Stormwind (a hidden place you have to walk through a house to get there), go to the second floor, and use /sleep emote while on the bed before finally logging out of the game. I did this every time.
Imagine my consternation when I found out simple walking in CP2077 was stupidly difficult and annoying. Why do I have to hold rightclick? Why does it zoom my view?