I think it's the centralization of services that broke what the internet was in the mid-00s, and increasingly monetized every facet of it. What was internet culture in the 00s became nerd identity in the late 00s-early 10s, which over the decade became completely appropriated and commodified by capital interests.

More of the internet now is intentionally constructed to cater to a market demand. In the 00s anyone could afford to run a publicly accessible web page fully designed by them. Now that's just having a profile on an existing social media site. Google was incredible because it helped you find the most niche type of internet site, but when everything became so consolidated it pivoted to advertising, cloud services, and venture capital. Now it's just a monster that seeds any technology they think would help them make profit and focuses the entire sector around that motivation.

More people are now on the internet to turn a profit as well, because it's now the primary place for business. Things you used to do on the internet for fun in your spare time are now career paths.