For data recovery of archival stuff it's better to keep it uncompressed, no?

So apparently zamadatix's point wasn't well taken, but I think it could be an effective approach to store the same data twice over to increase the likelihood of successful recovery. Could be even be even ten times, or e.g. 6+4 with redundant recovery coding.

Although you do have a point that the compressed data might be more difficult to decipher, if it doesn't have sufficient redundancy to skip bad parts, or if it is essential that the data is aligned in a certain way (e.g. disk images, and probably many other formats) and the format doesn't take this into account. Shorter window sizes, window reset markers, and explicit offset information could mitigate those problems.

Depends on the specific scenario. E.g. efficient compression can speed up recovery from slow media and provide space for increased parity.