I encode parts of my FLAC music collection to 96kbit Opus for the mp3 player that I use in my car, or just walking around. Cars and cities are noisy, and the earbuds I use aren't great, so I'm not concerned too much about the quality I'm leaving on the table, but it's good enough and the space savings are awesome.

Opus is the most used codec on the planet, currently.

Can't really get more popular than that.

I think you meant to say, "why didn't it get more popular for _pirates_"? Because pirates are purists and prefer lossless codecs (ie, FLAC), and even when they wish to use lossy, Opus being locked to 48khz (to reduce implementation overhead for low power SoCs) kind of pisses them off, even though Opus's reference impl includes a perceptually lossless resampler (ie, equivalent to SoX VHQ, the gold standard, and better than the one in Speex).

Examples of users: Discord, Whatsapp, Jitsi, Mumble, Teamspeak, Soundcloud, Vimeo, Youtube (but not Youtube Music), in-game voice chat on both the PS4/5 era PSN network and the Xbone/XSX era Xbox network, the new Switch 2 in-game voice chat, games that use Steam's in-game voice chat (ie, TF2), all browsers (required to impl webm and webrtc), most apps on Android that have their own sound files (incl. base apps in Android itself). Windows and OSX also have native OOTB support for Opus. Some "actual" VoIP platforms use Opus. Some phone calls routed over the LTE phone network use Opus.

It is also standardized by the IETF as RFC 6716, and most for-audio SoCs support Opus natively as part of their platform SDKs.

You're not going to find anything more popular than this.

But it is popular! YouTube's preferred format uses opus for most, if not all, videos upload in the last ~5 years (they also offer an AAC option alongside it). Several VoIP services use opus, including Zoom, Discord, FB Messenger, and WhatsApp (until recently). Opus is part of WebRTC and thus implicitly available for audio/video conferencing software that runs in the browser. And if you look up what audio enthusiasts recommend you use to encode your lossless music for smaller file sizes, it's almost always opus!

We have got to the point where we can afford to stream Lossless Audio file already. ( And then lossy re-encoded on the fly to our wireless earphone )

For higher bitrate 190 - 256 Kbps AAC-LC offers 99.99% compatibility, only losing to MP3 while offering near indistinguishable audio quality all while being patent free.

Opus does shine in anything lower. I am not even aware of a codec that is as good at 128Kbps to 160Kbps range. The lower end sub 96kbps is also competitive if not the best at certain domain. But for compressing music or pre-recorded audio it is a solved problem or non-issue.