on long distance trains first class seats are wider and usually only three per row instead of four.
on regional and local trains i have to agree the difference is less apparent.
i guess the main benefit is that first class areas are going to be less packed. i am not sure but it may be the case that you are not even allowed to stand in first class if you have a second class ticket.
so if the train is crowded then that crowd won't be allowed in the first class area, and it is unlikely that you buy a first class ticket without a seat. but if the train is only lightly filled it probably makes no difference at all.
on regional and local trains i have to agree the difference is less apparent.
i guess the main benefit is that first class areas are going to be less packed. i am not sure but it may be the case that you are not even allowed to stand in first class if you have a second class ticket.
so if the train is crowded then that crowd won't be allowed in the first class area, and it is unlikely that you buy a first class ticket without a seat. but if the train is only lightly filled it probably makes no difference at all.