You’re telling me for national rail tickets that involve Merseyrail, you can’t buy a ticket on Trainline?
Edit: You can but have to apparently collect it from a staffed window, which while I admit shows that apparently they are necessary specifically in Merseyrail’s area, doesn’t really apply to the country as a whole (and is really, incredibly funny to me).
Also, the fact that you can only collect it from a staffed window is really out of luck if you live at an unmanned station.