I've found it actually makes it easier for advertisers to track me - I tried turning it off briefly, expecting completely random, useless ads, but instead saw disturbingly relevant ads, which basically reflected a profile of the sites I visited regularly, for example, ads for products sold by random obscure sites I visit regularly. Not only that, but the ads followed me across sites.
Not entirely sure why that was but my guess is that by simply allowing ads to load, you're letting ad providers like Facebook/Google collect far more identifying information to improve their confidence that you've visited a given site, vs by not loading them all they know is their tracking/ad script was requested. Similarly, by clicking an ad you're now also visiting an advertiser's site, loading even more tracking.
For AdNauseum to achieve it's stated purpose, it would also need to visit random sites to pollute ad providers' profiles on you.
Valve would never sell fake digital goods. Hats? Gun paint jobs? Nahhhh that's beneath them. I mean worse still, NFTs can be traded on the secondary market, which would be completely ridiculous for a company to allow for cosmetics in a video game of all things.