Any compressor should have at least free access to source code, and also be 'restore' tested against a specific version artifact (binary) of that codebase.
Depending on the source data, I'm personally comfortable with Zstandard, 7zip / xz, or even gzip depending on a mix of how conservative the use case and how effectively each compresses that data structure.
I like zstd as a format, but it's too new for archival use -- it's only been available for five years or so. gzip is easily the winner; while it isn't the best compressor available, it's been around for the last 30 years, and is likely to still be in use another 30 years from now.
There's also the option to compress with one format now, and during routine data storage maintenance to use newer better storage layers, like compression. What's most important are integrity checks, redundancy / duplication, and the ability to repair to the source data stream.
Depending on the source data, I'm personally comfortable with Zstandard, 7zip / xz, or even gzip depending on a mix of how conservative the use case and how effectively each compresses that data structure.