That's not an implementation. That's a request to sites that you visit to comply willingly. An implementation would be defensive.
It's what you would do if you had the crazy idea that a browser should be a client for the user, and only a client for the user. It should do nothing that a user wouldn't want done. The measure of a client's functionality is indistinguishable from the ability of the user to make it conform to the their desires.
It's not realistic to completely prevent tracking solely on the client-side. Every time that you interact with a server, that's an opportunity to track you. You can't prevent unless you just completely stop interacting with the server.
It's what you would do if you had the crazy idea that a browser should be a client for the user, and only a client for the user. It should do nothing that a user wouldn't want done. The measure of a client's functionality is indistinguishable from the ability of the user to make it conform to the their desires.