The search for is not just about file formats or data rates. It is a search for fidelity. It is the pursuit of that final 10% of sonic perfection that turns a great song into a transcendent one. The piano should sound like it is in the room with you. The bass should vibrate your chest, not just your ears. The voice should break your heart with its clarity.
Many “FLAC” downloads on YouTube to FLAC converters are actually 128kbps AAC re-encoded to FLAC – audibly worse than original lossy.
Avoid random "FLAC downloader" websites. These often upconvert MP3s to FLAC (fake FLAC), which sounds identical to MP3 but takes up 5x the hard drive space. You can verify a genuine FLAC using software like Spek (spectrogram analysis) – true FLAC shows frequency information all the way up to 22 kHz or 48 kHz, whereas fake FLAC shows a hard cut at 16 kHz.