Answer: This setup prevents Muslims from having to lift our legs up dangerously high while trying to stick our feet in the sink one at a time. The alternative to that is we have to take a handful of water and pour it onto our feet below the sink causing the floor to get wet. Muslims also have to keep their feet clean before praying, which is obviously problematic in a bathroom where everyone pisses on the floor and walks with their shoes between the stalls and the sink, so you might see them trying to keep one shoe on while washing the other foot and then switching. It’s also why we take our shoes off before praying and use prayer rugs to avoid touching unclean things while praying.