If you're talking about analog archival that is a whole other ball of yarn, but in terms of digital then I would think that the thing to do is use only lossless

If you're talking about analog archival that is a whole other ball of yarn, but in terms of digital then I would think that the thing to do is use only lossless compression, bit-level fidelity error correction, and multiply-redundant, multi-region storage. You must plan on storage media, providers, and entire networks partitioning, disappearing, and failing.