Honestly, we don't need a _replacement_ for third-party cookies. They're not really necessary for anything. There's few websites that break without them (e.g.:

Honestly, we don't need a _replacement_ for third-party cookies. They're not really necessary for anything. There's few websites that break without them (e.g.: logging into Atlassian), and that's mostly due to bad design (given that every other login flow out there works fine). Their main use has been to track people, hence, we don't really need them at all.