a safety line that can potentially move side to side still is quite a lot more flexibility than just going straight up and down. also, these things are like th

a safety line that can potentially move side to side still is quite a lot more flexibility than just going straight up and down. also, these things are like the size of an arduino board so i imagine they're cheap to deploy, and easy to replace. plus, if you have a fleet of them, you can probably just have some on standby ready to go, as opposed to a fixed window washing style system.