A user agent should chiefly do what the user tells it to do, but if you pay more attention, you'll see how bad web standards can actually still screw over the user. Because if you make particularly bad web standards, the user agent can still do what the user is telling it to do, but the website can then start behaving in a manner which goes against what the user is telling their computer to do.
If browsers had implemented WEI, a chief use case was to allow websites to control whether extensions and adblocking could be used while browsing their pages. And the clever part is, sure, your user agent could implement WEI "wrong" and let the user do whatever they want, but the attestation would allow the website to decide which user agents pass attestation, so you can't just make a user agent that does what the user wants.
DRM and WEI are pretty similar as they're both technologies that require computer programs to restrict what you can do on your own computer (and DRM does what WEI does with browser choice but in a litigation way instead of cryptographically-attested way), but I will repeat this again for hopefully the last time:
Not wanting DRM in web standards has nothing to do with the definition of a user agent.
One more time:
Not wanting DRM in web standards has nothing to do with the definition of a user agent.
Seriously, stop ignoring this. It's not like I didn't already aggressively state it previously.
It would be nice if we could go back(?) to a world where the user operates their computer, not the computer operating their user.