In the early 2000s, dozens of academic math websites were made featuring Java applets with interactive geometry.
Now, nearly none are left and Java applets are long deprecated. There's still some similar sites and demonstrations but few are ever as comprehensive as those old sites (and considering the current state of the web, a pain to find). Also, Java applets and Flash somehow lagged considerably less than modern webshit attempts at the same.

It used to be that I could go online and spend hours discovering countless cool sites on whatever topics I could imagine. Now it's all buried in bot-ran blogs all copying from each other. Or is it that people no longer make cool websites? Most cool webpages I run into now are hosted on github, most cool articles on some large platform. Most people I know don't use the web outside of youtube, wikipedia, and social media apps. The web just isn't as fun these days.