Lots of people are focusing on excessive JavaScript and CSS but these combined are easily dwarfed by a single high quality image.

Try visiting Apple's website for example. I can't see how you can have a small page weight if your page includes several images that are meant to look good on high quality screens. You're not going to convince marketing and page designers to go with imageless pages.

Doom's original resolution was 320x200 = 64K pixels in 8-bit colour mode. Even an Apple Watch has 92K pixels and 24-bit colour (three times more space per pixel) now, and a 15" MacBook display shows 5.2M pixels. The space used for high quality images on newer displays is order of magnitudes higher to what Doom hardware had to show.