I am very slightly annoyed that people haven't moved onto Opus which gives you better compression and quality than MP3. MP3s are still useful for any older devices that have hardware decoding like radio sets, handheld players, etc. Otherwise, every modern device should support Opus out of box.
Hilariously, x264 has the same problem where there are direct upgrades with H.265 and AV1, but the usage is still low due to lack of hardware accelerated encoding (especially AV1), but like everyone uses FLAC for the audio which is lossless lol.