You can tell the difference between 320Kbps LAME encoded MP3's and FLAC? I think not.
I probably can't >90% of the time, since MP3 tends to truncate higher frequencies which we get less sensitive to as we get older. Still, just because I can't doesn't mean someone who's a bit younger or has more sensitive ears can't. Also lossless formats allow you to reconstruct the original stream or convert from one to another infinite times without a problem. MP3 may have been relevant in the 90s, but there is no need for it or any other lossy format anymore.