If trains are infrequent enough (every 20-30 minutes or more) that it's worth planning around the schedule, it's generally unlikely that the frequency will be changed significantly in any 10-year period.
Or the office could move, you could move, your office could change the time of the last meeting of the day etc...
Relying on the granularity of the train schedule to enforce work life balance is brittle at best, and it’s a terrible argument against WFH.