Also, a good railway increases profits elsewhere, in addition to fares, as people can cheaply and relatively comfortable travel across the country.

Correct, but Iryo is a private company, although the railway in Spain is publicly maintained i guess by Renfe. So i believe Iryo should make money, specially (as mentioned in another comment below) it's part of Trenitalia. But i'm definitely not an economist.

The public railway infrastructure is maintained by Adif [1], which is owned by the Spanish state.

[1]: https://en.wikipedia.org/wiki/Administrador_de_Infraestructu...

Trenitalia has to make money since it's partly a private company.

If it's critical infrastructure, it'll get nationalized anyway when struggling.