The origin of degrading web user experience lies in the ideological misgivings shaping the web: the web, as we know it since overcoming the bandwidth limits of modems, came to be while neoliberalism took over liberal governments and the TINA tenet obfuscated the fact that software can be infrastructure. Some should be infrastructure and not beholden to markets and their embedded incentives, in fact.
Building search engines, the interface to information, on a foundation of ad spending is folly.