"Perhaps I've misunderstood the concept of a faster internet connection..."
It's so that the advertisers can load up the web page with dozens of heavy scripts to track you and show you ever more (somehow still irrelevant) ads. It's why we bought more powerful computers with more RAM too-- it's all for the benefit of the advertisers. Whatever we can do to help them invade our privacy!
When I used to read print periodicals for specialty interests (like computers), I used to look forward to the ads-- I wanted to see what was available. Ads for things I would never be interested in still weren't annoying; I simply did not look at them (once I saw that they were of no interest, of course). They didn't blink or flash or make noise or block content or play videos or force me to wait before I could turn to the page I actually wanted to see.
Now, though, even if we ignore the obnoxiousness of modern web ads, they are often far less relevant than when there was no targeting (beyond selecting which publication the ad was going into) and no tracking.
Some time ago, I was on Youtube watching air crash disaster videos and something happened (I must have disabled the ad blocker for testing; I never turn it off under normal circumstances) and I saw an ad. It was for either Boeing or Airbus (I can't remember which). What?? I might be able to afford a scale model of an airliner, but that would be about it.
It's true that I don't usually see ads or allow tracking scripts, and surely this inhibits the ability of the advertisers to track my interests (by design), but nothing I have ever done online would suggest that I am an executive at an airline or any other person who has a role in selecting or purchasing multi-million dollar airliners. At best, the algorithm clumsily matched an ad about airliners with videos about airliners.