Odd, I found about 50% of such things don't work anymore.
A lot of things -- useful things -- provided as Java applets have stopped working lately as the browsers and Oracle itself have increasingly locked down what plugins can do and how they are integrated. There have been ever-increasing numbers of scary warnings about things like who signed what and ever more hoops to jump through just to publish or run an applet. The thing is, those are almost 100% artificial barriers put there by Oracle, Apple, Google, Mozilla, and friends. The underlying Java code that actually made the applet go in each case would probably still work fine today if the artificial barriers were removed again.
I agree about the current state of web app development, but unfortunately there are few organisations with enough influence to significantly affect the course of the industry, and for now their interests seem more aligned with the status quo than radical change. There are some interesting ideas around, web assembly for example, that might open up some more radical options in the future, but then there are always new ideas in the background in web development and all too often they don't achieve the critical mass of interest and support to become established. I guess time will tell.