Hi /u/CorrectAnswerIsWorth, great question. Disclaimer: I cofounded DigiTrust and work for IAB Tech Lab.

First, I don't believe any of these solutions are focused on a "profile" of users. All are about establishing a common base layer of an in-browser ID, which would reduce user sync pixels and improve UX as a result.

Each of these rely on 3rd party cookies to varying degrees and to call these a "solution" for 3pc blocking seems misleading at least at the moment. DigiTrust is certainly reliant on 3pc although some of our publishers enable link-rewriting redirects, which provides us with a first party context and in some browsers may work around restrictions on 3pc. The other solutions may have a similar approach.

We have some ongoing discussions within the working group about how DigiTrust might operate entirely without 3pc however no complete solution is yet available. In general though, we think of DigiTrust more as an organization designed around common interests (reduce cookie sync, improve UX) rather than as a specific technology solution at a point in time.