On Sun, 02 Sep 2018 00:47:52 -0400, Paul wrote:

It's a software soap opera.

I skimmed that wikipedia, and I agree.
It's a mess.

I agree though with your summary that the patents expired so moving forward
we should see the MP3 encoders/decoders integrated into the tool suites.

"... patents required to implement MP3 expired in most countries by
December 2012...The various MP3-related patents expired on dates ranging
from 2007 to 2017 in the United States."

They did cover Opus (and Vorbis) near the end.
https://en.wikipedia.org/wiki/Opus_(audio_format)
https://en.wikipedia.org/wiki/Vorbis

I guess that's why Opus is the default for the youtube-dl.exe program.