I am all for it but it would be hard to enforce. Ads are already hidden everywhere. Someone "review" a product? Most of the time it is a hidden ad even if the reviewer hasn't been paid with money for that. Watches a movie or a video clip? A lots of products are advertised through close ups on the logos, etc.
If there is a payment, there is a good chance to track it.
Even a sign on the street is basically an ad. That plastic cow or pig head telling you there’s a butcher or cheesemonger?
It’s basically an ad. Possibly one of the oldest type too!