The only argument I’ve heard that makes me go “OK, fine!” in favor of FLAC is that they forced a standardization of metadata.

FLAC is well-supported. But, PCM RIFF WAV files are triv-i-al. Any CS101 student can write a parser. They don’t need decoding.

2:1 lossless compression is nice. It’s quite a technical feat.

Meanwhile, as an old software engineer, I focus pretty hard on technical simplicity. And, the complexity ratio of PCM vs. pretty much else everything is a a very, very small number. Very small :p