CSS + animations + JS + HTML5 cannot be blocked without destroying the web site as well.
That's a lame excuse. There were enough 'not malicious' sites, there are enough sites now what treat you like a 3rd rate netizen even if you are on a 4k desktop in a landscape orientation.
If anything, Web is destro^W profiling itself for a narrow subset of mobile users for quite some years already, so I can't accept your 'blovk Flash' stance as anything having a substinence.
There were always user-unfriendly sites. It used to be possible to easily block the nasty content (Flash), now it's rather hard. It used to be possible to extract the interesting content (Flash) and save it without the junk website. Now it's not. Separation was an advantage.
I agree that the Web is narrowing itself down. One of the symptoms is not having interactive content clearly delineated from the rest.
You seem to come from the same premises but arrive at the opposite conclusion, and I don't understand your reasoning.
jokes on them now, I guess
not to mention flash content could run on a potato, while javascript is soon to see your processor as fried as a potato chip instead
the problems that html5, css and javascript could in theory 'solve' are a moot point when the switch to those technologies killed any enthusiasm for it.
Today? Just forget about saving some web based game someone makes because it's probably streaming its assets from some dynamically computed URLs