Discord routes over their own servers and uses a private I3Dnet backbone to spread the signals across the world. The latter is one of the reasons why discord video is very good.

If discord did any p2p there would be stories all over of people getting ddos-ed after joining a voice call / screenshare.

In general, discords tech is pretty solid overall. The platform itself is just getting shittier.

The closest I’ve been to an accident was trying to cross a very busy intersection full of pedestrians, cyclists and cars. Intensively looking out for them and wait for a safe moment, then missing a full sized tram.