Regarding ethics, my opinion is that it’s unethical to offer strong E2EE to the masses at scale, without considering the needs of LE.
Should my sneakers be made more uncomfortable so I can't run away too fast?
Should they be able to remotely disable my car?
Remotely open the blinds to my home's windows?
Should I not be able to install a front door that resists attempts at forced entry?
What's the line where Law Enforcement's wants merit consideration?
Why do you view it as unethical to not consider Law Enforcement needs wrt strong end-to-end encryption?
As an excellent example, Certificate Transparency has almost completely mitigated the potential abuse of compromising a certificate authority and using it to MITM traffic. Similarly, "binary transparency" or "software transparency" will hopefully eliminate the abuse of delivering a "special binary" to just one person that others have not received.
Part of the threat model is the belief that any system with a backdoor has any hope of "preventing abuses". The backdoor is the abuse, leaving aside all the misuses of it that will happen.