The web didn't go from streaming 480p straight to 4k. There were a couple of intermediate jumps in pixel count that were enabled in large part by better compression. Notably, there was a time period where it was important to ensure your computer had hardware support for H.264 decode, because it was taxing on low-power CPUs to do at 1080p and you weren't going to get streamed 1080p content in any simpler, less efficient codec.