One thing that i just realized is i don't know exactly when things got bad. I remember the 90s when we had to "go" online, when the digital was apart from the analog and we kept online and offline separate. I remember simpler sites, not as many ads, I remember a time before "feeds". However, for the life of me I can't remember exactly when it started to suck. It might be that I was busy with other things in life, but…
Whatever the date, it's tightly coupled with the explosion of internet-capable mobile devices.
My personal pick would be 2012, because that's when the Samsung Galaxy S3 came out and outsold its predecessor more than twofold.
Coincidentally that's when the small agency I was working for at the time started offering making pages look on mobile devices.
In terms of units the market for mobile devices peaked just four years later.