How did I miss zstd?
Here are my benchmarks for 2.3 GB of jsonl, on a laptop. Compressed size, compress time, decompress time; using defaults.
gzip 7.3% 21s 9s
bzip2 4.6% 251s 50s
bzip3 3.3% 82s 69s
zstd 6.9% 2s 3s
lzma 4.7% 51s 3s