People forget one advantage of FLAC over other compression methods: it's directly playable. You don't need to decompress the whole thing before you can start playing it.
That's an essential feature for a media compression format.
That's an essential feature for a media compression format.
At the same time, most compression formats are very unsuited to starting decompression from any other point than the beginning of the stream. I don't know how easy it is to seek in FLAC files, but to my best knowledge it's at least possible.
Of course there are FLAC players, but without one of those you would need to uncompress it to wav before playing.