Preventing this in the browser is actually pretty trivial for most sites. Simply block 3rd party cookies. If the site uses cookies to track sessions the request won't have your session cookie and won't work.
It's not up to browsers to prevent this. Just like how you can't rely on client side data validation you must always take proper precautions on the server. Browsers taking additional precautions to prevent this would be nice but it's not the whole solution and never will be.
Edit: If you're going to downvote this please leave a reply stating why. I don't understand an opposing point of view unless you use 3rd party cookies to track people across domains.
It's not up to browsers to prevent this. Just like how you can't rely on client side data validation you must always take proper precautions on the server. Browsers taking additional precautions to prevent this would be nice but it's not the whole solution and never will be.
Edit: If you're going to downvote this please leave a reply stating why. I don't understand an opposing point of view unless you use 3rd party cookies to track people across domains.