I don't mean to support or refuse the author's main points or analysis, but you might like to know that the Chrome team is currently working towards shipping the Topics API. I have strong opinions about it but I will try not to editorialize.
My high-level understanding is that they're going to run an ML model over your browsing history (locally on your device) to build a list of "topics" that you care about. Sites you browse can use the Topics API to pull a set of these interests from the browser to show you "relevant" ads. Mozilla has taken a negative position against this standard.
Aside, your second point is incorrect. The SteamDB folks have a public write up on analysis of the preload system: https://steamdb.info/blog/steam-download-system/