You're dead right, it would be the one killer move to remove a lot of perverse incentives, fix the internet, possibly even social media, and all live in a happier world. The whole economy would stop paying the ad tax to Google and Meta.
And it's not that impractical : just make a consumer-run search engine for products and services.
People already complain about having 10 differently monthly subscriptions for internet stuff. If you remove ads people will need 30 to do the same stuff they do now.