It’d be nice, but I genuinely don’t see how that could be accomplished without a constitutional amendment. And even then, you have the deeper issue of how to regulate speech that isn’t directly associated with the candidate. It’s not a big improvement if you have some billionaires just throwing their money around, while a candidate they oppose is legally barred from raising money. I don’t see a way to actually implement something like this in a practical way when the stakes are as high as they are. Ultimately, the reason this market is so big is because it truly is that important, and no amount of legislation can really change that. Block traditional TV and radio ads and it’ll just shift even more to social media. Block direct campaign social media ads and the money will shift to a bunch of bots and astroturfed viral campaigns, which can’t be easily blocked without also blocking individuals’ ability to express their politics, which would absolutely, and rightly, violate the First Amendment.

Edit: I’d also just add that the people at large ultimately play a role here as well. If ads didn’t work, if we actually formed our views and voting habits based on facts and policies and nothing else, then there wouldn’t be a point to ads. But we’re fundamentally emotional beings and so here we are.