A format for archives, that is contractually built to last, has an impressive test suite, is easily browseable, where blobs can be retrieved individually if needed and is already known everywhere ?
Not the file format itself but sqlite: Airbus is using it for its A350 line, so it is guaranteed they will do what it takes to keep it working as long as the plane exists.
Sounds like SQlite, yet again: https://www2.sqlite.org/sqlar.html