The trilemma is actually only a model of a decision tree in current time.
It does not apply if you include any kind of technological advancements.
Today, we build things far faster, far better, and far cheaper than things in the past.
A T-shirt today takes minutes of time (per shirt) from cotton bale to finished shirt.
It used to take one woman a month of her time to make a shirt.
(spinning, weaving, cutting, sewing)
The future of cryptos... (the far future... probably 50 years)
Imagine every group of people (a small community. They will call themselves a family)
And each of these groups has at least one techie person who will run a full node.
So EVERY group that is part of the currency-exchange system has a full node, and thus mining is 100% of the user base. And everyone confirms every transaction.
In this kind of environment the entire structure of the problem is completely different.
And thus, the terms of the current trilemma do not even apply. Are no longer a concern.
However! there is always the dilemma of where do you put your time. Each of us only has 24 hours in each day. And spreading it out to three goals... gives you a trilemma that can never be solved...