That'd be great, but the "how" is a much harder question. What counts as advertising? Because there's a reason Google, Meta, etc. have their fingers in so many different industries: every single thing that gets attention could be leveraged for advertising, even the act of suppressing mentions of competitors.
Should I be able to say "X product has been great, I recommend it!" Only if I'm not being paid, you say? How could you possibly know?
As discussed in the article, "propaganda" is illegal. So any discussion about how terrible trump is would also be illegal. Propaganda doesn't mean false, it just means it's trying to convince you of something. An advertisement. Heck, the article itself could be considered a form of advertising for legislation.
It's just so trivial of a concept to say, but the moment you spend any amount of time thinking about it, it falls apart. It's like trying to ban the Ship of Theseus from a club.