True, though I think variable bit rate MP3 is fine enough for most.
But the main reason is that it's so ubiquitous. If you're buying music, it's almost always MP3 unless you go to a source like Qobuz which serves FLAC. Same with devices - basically everything supports MP3. Vorbis and Opus support is far patchier.
> unless you go to a source like Qobuz which serves FLAC.
Apple is another odd one out there by only selling music as AAC, and Bandcamp gives you a comprehensive choice of all sorts of formats.
> Same with devices - basically everything supports MP3. Vorbis and Opus support is far patchier.
True that, though AAC support might also be somewhat reasonably common-ish these days. (Though I've found that apart from also having a relatively low folder count limit in general, my car radio also has some difficulties with reading the metadata in some files, and as far as I can tell I think the affected files are all MPEG-4 files. It's only some MPEG-4 files that are affected, though, but I haven't yet bothered to find out what exactly else they might have in common.)
But the main reason is that it's so ubiquitous. If you're buying music, it's almost always MP3 unless you go to a source like Qobuz which serves FLAC. Same with devices - basically everything supports MP3. Vorbis and Opus support is far patchier.