I submit that the reason the internet is boring is that these causes are all obvious to us, and this comment won't get upvoted:
1) apps created niche proprietary software everywhere that used to be free and open media
2) the declarative, idempotent roots of the world wide web have been replaced by imperative, brittle Javascriptified spaghetti code
3) Javascript build systems have largely obfuscated any code that can be seen
4) Web 2.0 introduced private social networks in walled gardens that in many ways offer fewer privacy guarantees than before (due to the profit motive of exploiting user info)
5) Monopolies and duopolies now receive the lion's share of funding for research (which tends to aim for increasing profits and attracting eyeballs instead of fundamentally advancing the state of the art)
I'll stop there. It's hard to say how many of these are fundamental impasses to having an open internet again..
I was on the internet in the mid-90's (I was 15 in 95 which I think is the year I got on the net, I'd been on BBS's for about 5-6 years before that) and it did used to be much more weird as a percentage of sites than now (though the number of sites was tiny).
As the grownups came along and commercialised everything a lot of that went away and back then if you wanted to say something online you had to learn HTML and what FTP was as a minimum.
So things were weird because quite a few early adopters were not techies by nature.
It's different now.
It's one of the reasons I don't use facebook, instagram, snap etc, they just don't stick for me.
I do use twitter but that is because it's a nice way to follow projects and programmers I admire so it has some utility to me.
I was an early user of reddit but since the redesign (on the back of cleaning up the community) the trend towards just another social network (EDIT: speaking of which https://news.ycombinator.com/item?id=19039571) is pretty clear at this point, it's utility is going down as is the quality of the average posts in the subreddit's I cared about.
HN has been fairly consistent since I join over the last 5 years, a testament to the effectiveness of decent moderation.
It used to be I checked HN after reddit but that switched over the last year or two.
I wonder if there is a way to combine the weird fun that was geocities/tripod/etc with the connections of a social network and modern ease of updating. Like how you use twitter, but for following webpages about butterflies or a shrine to the 6502 processor.
RSS - (partially) Google killed it.
My first website was about about TNG and why DS9 sucked balls.
Ironic since I now consider DS9 the better series (but TNG still has the truly stand out episodes, I think young me was just oblivious to a lot of the subtler stuff but I digress), it was shockingly bad (and I'd been programming since the 80's, HTML was just weird).
I spent about five years hating the crap out of it and never even considered web development as a career, if you'd have asked me back then I'd have said you'd claw the compiler out of my cold dead hands.
20 odd-years later and I do enterprise web dev (and C#/WPF and Java)