This is so NOT true.
Anyone with a pair of ears can hear the difference.
Try this very simple test.
Rip a good quality song that you like, twice. One in 256, and one in Flac. Have them back to back on whatever media player you're using.
Without changing anything in the audio between tracks (volume, bass, treble, the ridiculous Immersive sound settings, etc), simply listen.
You will immediately hear differences. How much different will depend on your source material, of course.
If you try this simple test, and you CAN'T hear a difference, then your one of the lucky few without the discerning ears to notice subtle differences, and should use the lower bit rate.
Most immediately can tell the difference. Many can't EXPLAIN the difference, but they can certainly hear it.
I used to be an IASCCA sound judge, and used to spend a lot of time tuning friends car systems for them. I mean a LOT of time, often keeping their car for a week. I had one friend who complained bitterly about how awful my tuning sounded. I was puzzled, as I thought it was sounding very sweet. I went back to his house, and we popped in some Floyd, and sure enough, it sounded awful. Turns out, he was listening to Pink Floyd downloaded from Apple Music at 256K. Took out MY media player, with FLAC, put on the same song, and the difference was clear and immediate, even to his ears, which are basically tone deaf. The differences are not always night and day, but they are discernable.