MIG wrote:

But the whole point of first class is so that people pay not to have to
sit next to people like you (or me).

Empty seats around them is the whole intention, which is ridiculous in
overcrowded trains. It would be better to get rid of the concept of
first class altogether. For anyone who really misses it on that sort
of line, where there is no tea service or anything, they just need to
bring a hanky with them to put on the back of the seat.

The worst I've found is on sub-urban commuter routes where very few of the
regular stock have first class but occasionally one gets put on. Naturally
hardly anyone's got a first class ticket and the result is either have
everyone squeeze into standard class like sardines or some have to go in
first.