[throwawaysbdi]

The rose tinting of HTML should also be taken into account. Java was maybe 10x slower in those days, but more importantly internet was 100x slower and computers 500x slower.

Java ran pretty damn good for what it pulled off back then. It would have been orders of magnitude easier to make Java into what we have today than it was to bastardize HTML and JS to be usable.

Java these days uses native UI which looks nicer and is much faster than in-browser rending. Graceful degredation is only needed because some browsers are such crap. This was never a big problem in Java and still isn't. If a JVM supports JDK 8 you can expect it to run java 8 apps reliably

Java seems like a resource hog because it will use spare ram when you've got it, but most apps run fine on around 15mb of ram. Less if you use AOT compilation. Modern webapps use around 50-100.