A while back, I set up a server that limits bandwidth through it to roughly max dialup speeds https://dialup.moveything.com/. It has some gifs, progressive jpegs that are fun to watch load, and a mirror of xkcd.

It uses rate limit buckets per-IP on the server side, applied before SSL termination so it doesn't include that overhead. If you open two tabs, they'll have to share. If your behind a NAT, you'll have to share with your NAT-mates. And, it also has headers saying not to cache anything, so you can continue to enjoy the experience.