Ask HN: What is going on with mainstream website usability?

Over the past two years or so, I've noticed that the basic usability of most of the mainstream websites I either try to read myself, or see linked by others, has massively deteriorated.

I'm not referring to making things screen reader friendly, or the UI/UX principles behind the navigation panels, etc. - I'm referring to the ability to scroll and read the content.

Admittedly I do a lot of browsing on an iPhone 6. No, not the most recent bleeding edge mobile tech, but still quite a fast "machine" to fit in one's pocket. Surely it should be able to handle reading an article, no?

Yet time and time again, between the ads loading one on top of the other, trying to hit a little "X" button that moves out of the way as I try to tap it (because some other ad has either loaded or decided to resize itself), I'll find myself scrolling and getting major lag - or the whole screen going blank and then refreshing, etc, etc.

The meat of my question is - are the engineers, product managers, and even top level business people that run these web sites even trying to use their finished product? Feel free to chime in if my anecdotal data is way off base, but I'm amazed the average person even makes it more than 1/3rd of the way through a typical page before giving up and moving on. How is this a net positive for the businesses, even with the advertising revenue? Are the engineers of these sites just constantly not being given time to fix such issues, or being over-ruled on poor decisions?

Sure, sites such as HN work just fine - however I feel like we (as engineers at the least) have failed that something as simple as reading static content should work so poorly given the power of modern devices.