I… stands for…’I’…and D stands for… Dentification!~Norm Macdonald
Perhaps I have written on this but quick notes for a future writing.
In regards to a decentralized Id system I think we are often missing the point, or solution, or the general purpose of ID. ID is like some form of a gate key in which the gate keeper only wants to administer someone that fulfills a certain set of requirements. A individual wishing to gain some form of access only wants to give the missing information (if any at all) required to prove themselves worthy for access.
For the purpose of keeping minors out of an adults only establishment for example, such a place only needs to verify age. The individual should wish to not necessarily have to reveal age sex gender eye color etc.
Ideal Id then is a formula with regards to the acceptable probability that someone is who or what they say they are, at the least possible cost to that individuals freedoms and security/privacy.
In some ways some form of 1 ID fits all solution might be acceptable, but in other ways such a solution is unnecessary and itself the privacy/security hole.
ID then seems to come in two parts: wants of the Identifier and wants of the Identified. Ideal ID then has male to female part type considerations (gender is irrelevant but its just a saying).
Lastly a larger catch all solution might be facilitated if every person on earth ran some form of a bitcoin node.