MySpace is a great example! I think a lot of web developers out there who now work for major corporations or started their own companies probably started out just wanting to add a gif to their profile or change the background color.
Sure, the results turned out ugly 90% of the time, but it gave people a way in. A way to just experiment and have fun.
Compare that with the front-end build steps new devs are expected to find their way through these day... it doesn't make sense. I think one solution work considering is making the browser and HTML itself take on more responsibility. Front-end libraries are just giant hacks built on top of them.