A couple of extra points. The article alludes to the need for through tracks although it is perhaps not immediately obvious that this can also be used for main

A couple of extra points. The article alludes to the need for through tracks although it is perhaps not immediately obvious that this can also be used for main "terminal" stations. In Germany, very few trains terminate in the Hauptbahnhofs (main stations) but instead will then move out, often to another large station or depot outside of the city centre. This allows high traffic into the main stations without blocking them up while cleaning/turning round. Another issue about level loading is made but it sounds like this is mainly related to the difference between a "road" at ground level needing steps vs a platform at carriage level. However, even in the UK where everywhere uses platforms, there are still issues with level due to the variation in track height related to ballast working so even "mostly level" can be a problem, particularly for wheelchairs and even done efficiently, loading these can easily take a minute or more. Thirdly, at least in the UK, it isn't just the build up of subtle delays that can be an issue but small problems creating large delays. The other week, trains were delayed and cancelled for hours (for some reason) because a trespasser was seen on the main line and needed to be found by the police. One relatively small and common occurance affected 1000s of travellers. A single signal problem, a broken rail, failed point etc. This means that you could in theory run e.g. Kings Cross Station with fewer platforms but as soon as there is a problem, people don't want to sit on a train for 2 hours somewhere on the line. Having more platforms gives you that flexibility.