There were a lot of X-extensions introduced over the years that are rendered server side. Some are even widely used even today, such as Xft. Also the ability t

There were a lot of X-extensions introduced over the years that are rendered server side. Some are even widely used even today, such as Xft. Also the ability to upload pixmaps and blit them afterwards as much as you want without causing much bandwidth exists since the earliest version of X11. The offending toolkits are not even using that. They blit client side and transmit the result every time. As I told you, they are stupid.