Oh man this is a nice idea, I will try to add on somethings which I can think about from the top of my mind

To be really honest, even if things were publicly broadcasted, The amount of choices of products we make in each day would be huge.

So no random stranger would go and look for your product choices. What would matter are the close friends and family or perhaps when one becomes really famous?

Would the fundamental idea of anonymity go away from all internet? Like if someone posts a youtube video or even a yt comment, would I get to know what they ate for dinner?

Can ads still be blocked? If my product choice is an LLM lets say, would my prompts be choices as well that will get leaked with the conversation to everyone?

To be really honest, Govt.'s (snowden showed us) already can know about your product choices pretty good enough and the internet/infrastructure behind it is pretty centralized nowadays as well

Sure there are alternatives but how many people do you see using beyond the tri-fecta of cloud and how those choices come downstream to us consumers if services run there

I feel like this is gonna be a classic example of Hawthorne effect (Had to look the term for that) meaning that people will behave differently now that they are being observed.

Also do you know that its not any technical limitation which limits it but financial incentives.

There is no incentive to having your product choices be publicly broadcasted but for the services, there is an incentive of money if they show you ads and which they end up showing to ya.

If there was an financial incentive for the servers to create this choice itself of opting out / public broadcasts option, they probably would be reality.