I'm not sure how you got that impression. Attestation doesn't require any sort of scans on your current memory content, only the hash of the code that was executed.
It could ensure that an employee laptop is not infected when connecting to the intranet which could prevent customer data leakage which would be a benefit for all of us.
It would only ensure that the laptop user does not run software that is not approved by Google or similar, a DRM, as Trojans will continue to find ways to disguise themselves and insert themselves into authorized processes.
The company would find difficult to run custom software not covered by such DRM. In time, the Web Environment Integrity API organisation would say that there are too many authorisation requests or similar and demand economic compensation from developers to be included in the authorized filter scans, at time the supposed initial objective is not accomplished, as this DRM does not ensure the laptop is not infected.
Such a scan would take like half an hour. You need to scan each unloaded executable. WEI won't be used for that. It will be used for blocking ad blockers and ensure Google's malware is active.
I am quite sure that the client programs need to be cooperating for the WEI to be practical.