That response is almost 10 years old and completely outdated. I've designed and maintained a national media service and can confirm that on the fly transcoding is both cheaper and easier. It does make sense to store different formats of videos that are popular at the minute but in the medium to long term streams are transcoded.

I'm traumatised from reading this.

It's transposed on the fly, this is a fairly simple lambda function in AWS so whatever the GCP equivalent is. You can't up sample potato spec, the reason it looks like shit is due to bandwidth and the service determining a lower speed than is available.