Blah blah blah bitrates blah blah blah.
Bitrates aren't a good comparison because the encoding for streaming is different. It's like comparing MP3 and AAC. The reality is, 4K streams from iTunes are arguably better than standard Blu-ray, and the difference between it and UHD Blu-ray is likely completely negligible to anyone who isn't going out of their way to examine a single frame and go "aha! I found a difference!" Like yeah, sure, if your gonna nitpick it then uncompressed always beats co pressed, but that's missing the point. Everyone embraced AAC and MP3 because the compromise was worth it. Save a lot of data bandwidth in exchange for negligible decrease in quality. Now, sure, the difference for standard streaming is fairly stark, but it's no longer the case for 4K streaming. 4K has reached that sweet spot that mp3 did. There will always FLAC fanatics and the video equivalent, but they are a tiny minority. Unless your a paranoid pixel counter, then yes streaming has caught up.
This will be called a hot take or something. Lol.