Additionally, I strongly disagree with your assertion. Adding any kind of scanning system like that is technically infeasible unless you sacrifice some measure of security. The government and many nation states have been trying to argue against encryption of various levels (even less than end-to-end encryption) and the ultimate outcome is it being rejected because all of those measures _meaningfully weaken the security of the system_.
this is beyond naive.
the reason these measures have been rejected is due to public outcry and bad press for the governments trying it. the US banned exporting functional encryption for a long time, Australia passed it's you-must-assist-security-services bill, every country has LI systems embedded in etc etc. the LI systems hugely reduce security, up to and including mass infiltration by the US of an ally: https://en.wikipedia.org/wiki/Greek_wiretapping_case_2004–05
if you think "that'll make things less secure" is actually going to stop these constant attempts to eliminate private communications, you're going to be hugely disappointed by the next ten years.