Well third party javascript makes a lot of people money how do you propose we get around their buying power?
Also what would the limits be of third party javascript be? Would it be allowed on the domain level so people could still use CDN's and other things easily such as cdn1.example.com, etc... if so It probably could be okay then people could use CNAME or A records to link to their legitimate third party javascript like analytics and ads and it could take away a lot of the possibility of malicious third party javascript.
The web however would probably have to change a bit because a lot of websites use third party javascript depending on your definition of it such as google's 1e100 domain and other such cdn measures that aren't necessarily served from a domain record.
Also what would the limits be of third party javascript be? Would it be allowed on the domain level so people could still use CDN's and other things easily such as cdn1.example.com, etc... if so It probably could be okay then people could use CNAME or A records to link to their legitimate third party javascript like analytics and ads and it could take away a lot of the possibility of malicious third party javascript.
The web however would probably have to change a bit because a lot of websites use third party javascript depending on your definition of it such as google's 1e100 domain and other such cdn measures that aren't necessarily served from a domain record.