This is likely going to be the dumbest question of the year, but Why can’t we do our own federated web standards?
The web is already federated. Anyone can start their own web server and compete with everyone.
The problem is WEI will prevent you from using unauthorized browsers with, for example, Netflix or YouTube or your bank, if those services decide to force WEI.
Federating those services is near to impossible for various reasons. People could make competing services that don’t enforce WEI, and some people have.