YouTube adding a higher quality feed does not degrade the service. I don’t know how to put this in planer language.

Serving video is expensive. Serving high Bitrate video is extremely expensive. Storage costs have stopped scaling. Do you want them to provide a sustainable service or run at a loss to hike prices later when competition died? That’s not how YT operates. They are profitability and creator revenue first.

They made bad choices with shorts, sure.