I’m getting a bit off topic, but how often would one encounter an escalator on Shabbos? Elevators, on the other hand, are fairly common, even in old buildings.
I mean, just in terms of cost/value, an escalator only connects two floors together, whereas elevators can service many floors.
Plus, in terms of building design escalators need ample horizontal space most often found in resort or casino hotels, train stations, airports, etc. (I have seen one in a supermarket in FL), not the typical shul, apartment building or average hotel.