> even if it would be possible to buy that same ticket from a machine at the station or in-person at a ticket office and it would be perfectly valid for said se

> even if it would be possible to buy that same ticket from a machine at the station or in-person at a ticket office and it would be perfectly valid for said service. You can also buy a ticket which is nominally for a different train online, which will still be valid so long as it's not an advance ticket. But I agree this has bad UX.