If server side rendering and a subset of js were sectioned off, the browser could have an alert icon that says "this website has dreadful performance, click her

If server side rendering and a subset of js were sectioned off, the browser could have an alert icon that says "this website has dreadful performance, click here to quarantine it" that allows people to disable js forever. Websites could comply with the new standard or risk being user quarantined. Not completely unlike Apples handling of flash.