What I meant is yeah, you are right about that, but no, lossless formats aren’t called lossless because they don’t lose anything to the original, they’re called lossless because, after compressing and decompressing, you get the exact same file that you initially compressed.
Another commenter on this post explained it really well.
By your definition, PNG isn’t lossless because it’s not an exact representation of every single photon of a picture that was taken. You’d need infinity pixels in order to be completely faithful to the “analog” thing that you’re trying to picture, in the same way you’d need infinity points to completely translate an analog wave to digital.
When you compress anything with FLAC, you will get the exact same thing you compressed out, so there is no data loss.
Of course, that wave which you compress will not be faithful to the analog thing, but that’s just a limitation of digital computers.