"Dead internet" isn't a theory. You can go on YouTube right now and find hundreds of channels telling people in third-world countries how to get "rich" (relative to the rest of the people in their country) by posting YouTube shorts promoting right-wing talking points from US-based IP addresses. This money is paid out by far-right organizations, separately from YouTube adsense revenue.

The so-called "silent majority" is nothing but a bunch of teenagers running sock puppet accounts posting shorts behind VPNs for $0.10 USD per one million views from countries like Latvia. These people don't know anything about US politics or even live in the US.