It's the user who are agreeing to the TOS by visiting a given website. Google cannot define TOS for any other website. They can however do it for their own webs

It's the user who are agreeing to the TOS by visiting a given website. Google cannot define TOS for any other website. They can however do it for their own website. But then, since it's the user who visits the website, why should an extension designer be responsible? And it would be crazy for anyone to go after each user without making a big mess.