That sounds SO great.
Obviously there are no realistic security measures that are 100% effective. All this will amount to is further cementing the power of large internet companies. You know this, so why ask for it ?
A not insignificant part of the large Internet companies power comes from that they are the only ones who can handle, or people trust to handle, security. It isn't that hard today to create your own e-mail system or smart phone. But managing those systems, especially for a reasonable cost at scale, is just beyond what most new entrants in the market can handle.
Everything can go wrong.
> A not insignificant part of the large Internet companies power
So it's about breaking the power of large internet companies ? Figures. Can we please do that WITHOUT destroying the web ? The last regulation that tried to break the power of large internet companies was the GPDR, and that has significantly entrenched the position of the large internet companies instead, while creating a ridiculous amount of inconvenience for everybody. This ... will do the same.
People WANT to share that data. Or perhaps I should say, they want the things that happen when they do. Quick searches that get them the products they want, on Google, on Amazon, on clothing shops and on tons of small webshops. Even the obnoxious image ads. People want them.
That means that a login mechanism will just be an extra hurdle with zero of the effects you want.
So ... perhaps not.