As I said in a different comment, I think this is simply the wrong optimization. When you are running to your stop you better know already what train you want

As I said in a different comment, I think this is simply the wrong optimization. When you are running to your stop you better know already what train you want to take. Plan the route then go to the platform instead of get to the platform and panic about what train to take. I never ever had to "check every platform individually" and this was never something that took any time because this was never an action. The flow was always, decide on a route(choose train)->buy tickets if needed->get to the station->check the central announcement panel for platform corresponding to train number->get to platform->get on train. The choice was already made in the first step. The only difference before the internet existed was that ticket purchase was done after getting to the station. The choice of train was still done ahead of time using the train book or the train information telephone line.