jpg: webp, avif, jxl. The first two are adopted because of non-negligible gains, the latter because of features missing in jpg.

mp3: Both AAC and opus have non-negligible gains and both are fairly widely used.

zip[1]: lz4, zstd, and lzma2 dominate at least gzip's implementation of deflate: For any given setting of gzip, there is a setting for at least one of those three that is both faster and smaller.

1: Not a codec; the zip format specifies a dozen methods for encoding. I'm assuming you mean Deflate, which is the most common compression method associated with zip.