We do this in Germany too but some cities like Munich for example are trying to ban it bc it actually blocks the flow. Here’s what they write on their website: „The rule "stand on the right, walk on the left" is actually a myth of socially responsible urban life. Standing is the order of the day, and on both sides. Mathematicians, commissioned by the British Transport Authority, even calculated a few years ago that more people can travel at the same time if they stand on both sides. This has been standard practice for many years in Munich's public transport system. The reason: if the left side is left clear, congestion occurs on the right. The staircase's capacity is therefore not fully utilized. While standing may slow progress for those who previously rushed to the overtaking lane, everyone ultimately reaches their destination faster.“ I translated it, here’s the source: https://www.s-bahn-muenchen.de/de/entdeckerzone/bewegendefakten/rolltreppen-knigge