The courts already distinguish "commercial speech" as a class of speech. Would we prevent all forms of commercial speech? What about a waiter asking you "would you like to try a rosé with that dish? It pairs very well together." Is that "advertising" that would need to be outlawed?
What about giving out free samples? Is that advertising, and thus should be illegal?
What about putting a sign up on your business that says the business name? Is that advertising?
I hate advertising and propaganda. But the hard part IMO is drawing the line. Where's the line?
The biggest example that comes to mind is gambling. Japan says it's not gambling if the pachinko place gives you balls and then you have to walk next door to a "different" company to cash out the balls. I say it sounds like their laws are captured by the pachinko industry.
Video game loot boxes are technically legal but most of us don't want children gambling. Even if the game company doesn't pay you for weapon skins, there's such a big secondary market that it constitutes gambling anyway. Just like the pachinko machines.
It wasn't just the pachinko industry that tied the hands of Japanese government. It was the people too. It's a lot harder to ban something and keep it banned when everybody wants it. Thankfully, not many people want ads, but pachinko was popular enough that it makes sense to continue to let people do it. You're right about still getting a benefit. Even after carving out exceptions, banning gambling broadly otherwise is effective enough to solve a lot of the problems that unregulated gambling can cause.
I do think video game loot boxes are something that needs regulation. Not just because it is gambling, but because the games can be unfair and even adversarial. Casinos exploit and encourage adult gambling addicts but at least those games are required to be "fair" (no outright cheating) and they have to be honest about how unfair the odds against you are. A supposedly impartial third party goes around making sure casinos are following the rules. Video games don't have any of that and they're targeting children on top of it.