From my own observations and talking with lots of residents, plumbers would come unclog at the street level or somewhere inside the lower floors of multi-story

From my own observations and talking with lots of residents, plumbers would come unclog at the street level or somewhere inside the lower floors of multi-story buildings. Most people I asked said it happened pretty routinely, sometimes multiple times per month. I'm not sure a plunger would help much for a blockage 20+ meters away.