But yeah, as storage space & bandwidth are less and less an issue, if FLAC is fully supported across the board, the scale should be tipped. My worry comes from we not quite being there yet.
Sometimes I'm just baffled by how broken the Apple ecosystem can seem.
There’s a handy app called XLD (X Lossless Decoder) that will convert from FLAC to ALAC (and probably back) in a couple clicks if you need it. Lossless means I don’t really need to care whether my music is in an equivalent format, but I will admit it’s a bit silly.
FLAC is great because it's future proof. You can transcode to other formats as needed but keep a lossless archive.
There's already a whole bunch of them
On the second point, ALAC works just as well as FLAC in that regard.