Which layers? Do those lawyers have the competence to handle securing such a key? What happens when those keys are compromised? What is a legal order that would be valid? The US already has warrant exclusions for “emergencies”, how careful will these lawyers be when they’re getting thousands of requests a day? What happens when they get an NSL?

What happens when you’re investigating a criminal act sponsored by one of the governments you supposedly trust? What if they compel the lawyers in their countries to not provide the keys?

I generally dislike “what if” but given the problem space you do actually need to explain how your system works, and how it resolves these problems.

Remember there are plenty of countries with terrible human rights records, but they also still have regular crimes happen.