I flew SW for the first time a few weeks ago (I live in France). The flight was great but I discovered something I have never seen elsewhere : the bus stop plan

I flew SW for the first time a few weeks ago (I live in France). The flight was great but I discovered something I have never seen elsewhere : the bus stop plane. I flew from Phoenix to Oakland with a stop in Portland. The ticket was PHX-OAK, people got off the plane at Portland, some more got in. A bus stop in short. It took 2.5 + 1.5h for a nominally 1h40min flight.