> "Users often depend on websites trusting the client environment they run in."
Nope, websites depend on the advertisers trusting them. WEI is solving a website vendor problem, not a user problem.
> "The web page executing in a user's web browser"
From a user perspective web pages "render" in the browser, not "execute". Vendors that want "execution" on a client machine should distribute a rich client app, where many OS platforms already support environment attestation. WEI is web page vendors wanting to have their cake and eat it.