I can understand why a big streaming provider might want to use a lossy codec from a bandwidth cost perspective but what about in the context of streaming in your own network (eg through Roon or similar)?
In my case - I have an internet radio station available in a few different codec/bitrate combinations. I generate a chained Ogg FLAC stream so I have in-band metadata with lossless audio.
The stream gets piped into a process that will encode the lossy versions, update metadata the correct way per-stream (like there's HLS with timed ID3, there's Icecast with chained Ogg Opus, Icecast with AAC + Shoutcast-style metadata).