I'm very bad at hoarding and acoustics but here is my reasoning:

1. WAV and FLAC are both too big for me, my hard drive space is limited, and it would be better to have a compressed audio format with good quality. I don't care about transcoding, all I want is to store stuff that I can listen to without a hassle.
2. MPEG 2 died a hundred years ago, MP3 is dead too since the 2000s, MP4 could be an alternative but I'd rather have something more open.
3. OggVorbis is open and a good idea, but it was too boring to gain momentum.
4. Opus is an improvement to OggVorbis, and even if it is still "experimental/beta," it may be what I'm looking for (see https://en.wikipedia.org/wiki/File:Opus_bitrate+latency_comparison.svg). It is open-source, and has no patents or weird stuff.

So, is Opus good for me? According to a lot of web pages (e.g. https://audioutils.com/blog/opus-bitrate-guide), "At 128 kbps stereo, Opus is effectively transparent in ABX testing," and "At 192 kbps stereo, Opus exceeds what virtually all listeners can detect as different from lossless source."

That's why I chose Opus 192 kbps for all my music. The sound is "almost" perfect, my shitty ears will never hear the difference with a good FLAC file, I can store it on a server and copy the files to my phone without additional tools. And the files have the same size as the MP4 format with better quality.

All I need is: download the FLAC on Soulseek or Bandcamp, compress the files with the opus tools, clean the tags with https://picard.musicbrainz.org/, and store the result on both a hard drive and my phone.