The biggest form of this advertising isn't actually done with the knowledge of Reddit. Organizations use Reddit accounts to astroturf narratives together, since Reddit is pseudonymous. Companies who need better PR, or just a good controversy, can do this much more cheaply on Reddit than any other internet forum.

Still, the high-quality advice on Reddit that is authentic can be the most useful stuff on the internet.

True but, for example, I still find that restaurants and travel advice is far superior on Reddit than Google.

Reddit is often my starting point for beginning research on purchasing decisions.

Although when buying a digital piano, I ended up finding dedicated boards like pianoworld to be better

EDIT

Ironically, I also find YouTube to be a great source of research, mostly because the cost to produce content is higher and I think it's somewhat harder to produce inauthentic content (at least to me so far for the things I am researching)

or download alternative mobile app becouse they allow it, and use adblock