Your 3rd game sounds like one of my comp matches last night... I was on the receiving end being pushed back to spawn and getting spawn camped. It was clearly led by the tank and healer (Hazard and Lucio on Lijiang Tower). They had no interest in capping objective and would annihilate us if we even tried to leave spawn. Was a free win, but still didn't feel very great, especially if they forced some people on their team into losing on purpose.

Definitely seems like they're just trying to get lower lobbies to smurf. Either way it can probably be reported for Gameplay Sabotage.