No you can buy a reservation without a train ticket in
Germany
Austria
Switzerland
Czech Republic
Hungary
Sweden
(France)
Slovakia
Denmark
And probably more countries, thats just the ones I know from my memory where this is possible
It’s like an airline showing the first class seats as avaient in the seating chart when you bought an economy ticket
No it's not, because the reservation is a separate service. You can buy it from the train operator but you might have obtained your ticket from your own national train company, or you bought it later on, or you have a flexible ticket and don't know if you will make this train and it's busy (your right to your seat goes away after 15 Minutes of departure), or you buy it for someone in your family. It's just easier to not have this check included. Everyone in these countries knows that you still need to own a valid ticket for this class for the reservation.
I've never been able to buy a reservation without a ticket. It is usually buy ticket -> buy seat is you want one or get a random one if not.
Perhaps 20 years ago but not today.
Edit: if train ride continues with another company, seat is still managed in my experience.
Or here in the Swiss Railway App, to give another example ("Nur Sitzplatzreservierung" means "Just Seat Reservation")
And the other carriers in the list I've made above allow it as well
It is usually buy ticket -> buy seat is you want one or get a random one if not. Perhaps 20 years ago but not today.
No, not buying a seat doesn't guarantee you a seat on the train. Only if there is one available, which is the case most of the time (only during very busy services/timesthere might be no seats available (e.g. December 23))
That's not how countries with trains without mandatory reservations work. And that's the majority in Europe
SJ (Sweden) and VY (Norway) did not have this option. DSB (Denmark) does. How strange to allow only buying seats instead of changing an existing booking.
Edit: looked at https://jegy.mav.hu/ and could not find the option to buy only seats. It seems like this way of handling tickets is intermittent.
Sweden and Norway are countries with global price ticketing (Mandatory Reservations, integrated with Ticket/ SCIC-IRT), Denmark and Hungary not, so no surprise there (SCIC-NRT)
I don't think it's strange, it gives just more flexibility.
EDIT: Also it's nearly impossible to do international ticketing to Global Price Countries with more than a change or outside selected connections, whereas such problems don't exist in Countries that use SCIC-NRT, another Reason why Trains with Mandatory Reservations suck