The problem with the reservations is that they are a) complicated (you need to go to a different website), b) expensive (reservations should be free, and included in the ticket) and only for a small part of the available seats.
So on that train you have two situations nowadays:
- The whole train is crowded.
- Only the part of the train where people have paid extra is crowded.
So you are paying extra to be in the more crowded part…