Because it’s more expensive to produce I’m sure and to be honest probably not enough people care to make it viable for profit IMO.
A good number of SACDs (many by sadly now-defunct Telarc) were recorded in multi-channel versions. While they sound tremendous when done well, they really never caught on, and I have not seen that many done recently. Kal Rubinson at Stereophile is a big advocate of multichannel recordings, and in the past has reviewed equipment and SACDs that produce multi-channel sound. I guess that space and cost issues have limited its appeal, and record companies.probably don't want to incur the extra expense and trouble for what they consider to be a niche format.
Interesting taken from Wiki"
Stereophonic sound, or more commonly stereo, is a method of sound reproduction that recreates a multi-directional, 3-dimensional audible perspective. This is usually achieved by using two independent audio channels through a configuration of two loudspeakers (or stereo headphones) in such a way as to create the impression of sound heard from various directions, as in natural hearing.
Because the multi-dimensional perspective is the crucial aspect, the term stereophonic also applies to systems with more than two channels or speakers such as quadraphonic and surround sound. Binaural sound systems are also stereophonic.
Fascinating comments above. I guess another huge obstacle is all the Cable connections would have to be increased coming out of the back of the components if you expand from two channel listening to more channels. Vastly complicating the cabling and connectivity issues of the components.
If you have a good speaker system and great amplification, I guess the benefits are marginal. But there did seem to be openness in comments that there is potential it could be actually better.
Because I have nice speakers and amplification, including lots of tubes, I tend to listen to my home theater with two main speakers, eliminate the center channel and leave in the surround rear speakers . Often times this is a lot better. But other times you need the center speaker so the dialogue is more discernible and doesn't disrupt what's going on in the main speakers. This configuration can be handled toggling back-and-forth between two settings settings on the home theater remote. Ie. Super easy to go back-and-forth.
So at least on the home theater side I have the flexibility and it is working out really well
There are now hundreds of Dolby Atmos remixes of classic stereo recordings. It’s not generally understood that Atmos is a superset of Dolby Digital 5.1, and Atmos content will be automatically down mixed with no loss of fidelity to 5.1 if the AVR does not support Atmos.
My setup is: AppleTV 4K -> HDMI -> Marantz AV8003 pre/pro -> Marantz MM8003 power amp -> 5.1 speakers. This receiver dates back to 2010, long before Atmos, but the AppleTV automatically sends discrete, uncompressed 5.1 channel PCM to the AVR. Sure enough, the Atmos mixes play back perfectly in 5.1 surround, and are quite different than the 2-channel mixes. And there are hundreds of titles in Apple Music in Atmos format ... some new, some going back to the late Sixties, like The Doors.
True, the quality of the mixes vary, as it always has for surround sound. Some are very much better than the stereo release, and others are gimmicky and not very good. But most are an improvement on the stereo version, which are only a few clicks away if you prefer that.
Apple Music lets you choose tracks in several formats: 44.1/16 CD resolution in stereo, 96/24 resolution in stereo, and Dolby Atmos, which appears on the faceplate of the receiver as 5.1 PCM Discrete (not Dolby Digital). Based on the display, it is the AppleTV, not the receiver, that is decoding the Atmos stream and converting it to uncompressed PCM streams.
Yeah I mostly see uncompressed PCM which my NAD processor calls ‘Direct’ and that’s mostly what I see these days. And I’m fine with that.
YouTube videos with music tend to be better in stereo as it mangles things when some of the signal flows through the center speaker at times. A lot of the music through YouTube is pretty darn good. That’s interesting Apple allows you to change formats but I’ve never drifted into Appleland. Unfortunately roon does not do that as far as I know. Or maybe it does in some of their DSP crap which I tend to stay away from.
While there are a lot of multi channel recordings out there such as the suggested Eric Clapton Crossroads, any decent AVR or surround sound processor can already simulate full surround on any standard stereo recording. For music, you are not sitting on stage among the instruments, so back we go to the surround on the multi channel recordings just filling in the ambience of the venue. When we play simulated surround with regular stereo music there seems to be more content from the simulation and the channels are carrying more actual music on the surround channels than an actual recording done in surround. Both are good IMHO. If you want music from all channels your only limitation is your system. If you want to feel like you are sitting in the middle of an arena, the actual surround recordings would matter more. In any case I doubt studio recordings done in multi channel would be much better than the computer inside the AVR would create. I'm playing more and more stereo music through the surround sound processor these days, and it's pretty good. I would say this is also dependent on your system having full range capabilities for all channels or close enough.
Definitely requires an AVR that offers a "pure direct" or similar option, and does not in any way apply to the cheap low end units out there. There is no reason that a high quality AVR or processor when properly built for the purpose cannot also deliver top-class 2-channel audio. I know for example that mine shuts off all other circuits that are not needed and deliver a direct signal from source to amp. Even the display is disabled so not to interfere. Definitely requires specific hardware built for the purpose, and some will still argue. Then again some here talk about "breaking in" copper wire, so we will leave that right there. :-)