Not just the size of a given output, but the space of possible outputs. I am also of the opinion that webdev is bloated and miserable, but it is still a massive compression of the information it represents.
I don't really buy that acres of whitespace and gradients really describe much information.
Considered at the boundary of your awareness--in that you are mostly unaware of all the pixels on the page, then absolutely not true. A typical news article might be a few KB of text but MBs and MBs of images that you never look at.
I'm talking about Shannon Information specifically. In which case, acres of whitespace and gradients very much are information. Calling them "whitespace" and "gradients" is a significant act of compression in and of itself.
I understand your argument, but even then I don't think it's quite right; there is lots of room to improve on the size of a webpage vs its rendered pixels on the screen, even with the fancy fonts and gradients and animations. I still don't believe it's really megabytes. Have you seen 4k demo contests, btw? https://www.youtube.com/watch?v=0w_xEUoK79o
Considered at the boundary of your awareness--in that you are mostly unaware of all the pixels on the page, then absolutely not true. A typical news article might be a few KB of text but MBs and MBs of images that you never look at.