I'm starting to hear recruiters and coworkers reference levels in levels.fyi, e.g. "L6 at X company equals L5 at Y company" etc. however personal experience suggests these relative levels have changed over time. I don't see any mechanism to keep these updated. Ideally they should be calibrated based on TC and scope.

Scope is another area I think is subjective. IMO levels.fyi overindexes on breadth of scope and does not place enough weight on depth of scope.

Perhaps more interesting would be a comparison of say L6 at X company taking an offer at L5 at Y company. How many people were interviewed for L5, how many received an offer, how many accepted an offer.

If like 90% of people accept offers from L5(Y) => L6(X), while conversely L6(X) => L5(Y) only has a conversion of 20%, then it would show that L6(X) is more desirable etc.