ARC and CEC are only necessary because of this stupid situation where TVs are like displays with shitty media centres built in. ARC is only a tiny bit more convenient anyway; it's not that hard to run an audio cable back from the TV to an audio receiver and you'll be hiding the cable anyway so it matters not the slightest what it looks like.
In 2002 there was XBMC (later renamed to Kodi). Microsoft even had Windows XP Media Centre Edition in 2005. At that time it was perfectly possible to set up a media centre that could do everything. No need for shitty TV remotes and CEC. You would use a much higher quality remote of your choice. Oh how far we've come in 20 years...
> it's not that hard to run an audio cable back from the TV to an audio receiver and you'll be hiding the cable anyway so it matters not the slightest what it looks like.
That's fine for regular ARC which is basically the same capability as spdif, ATSC audio and DVD audio. But there's no consumer audio cable that has the capacity for lossless surround except for HDMI, and then you really want eARC because otherwise you have one HDMI running from the receiver to the TV for video (and maybe audio) for sources that can go through the receiver, and a second HDMI that runs from the TV to the receiver for audio only for sources that can't go through the receiver (built into the tv like the tuner, network streaming, and playback from USB; and also devices that exceed the HDMI bandwidth of the receiver or don't negotiate to an appropriate video and audio format unless going direct --- I have a 4k Roku and a 1080p BluRay player that need different settings on the TV to work through my receiver, or I can wire one source direct to the TV and use eARC)
In my experience multi-channel AAC gets sent as multi-channel LPCM over HDMI, whether that be eARC or not. That's fine though, I don't really care what part of the chain does the AAC decoding because it has to be turned into LPCM _somewhere_.
Speak for yourself but I'd rather have LPCM surround audio than deal with proprietary formats like Dolby Digital and DTS which are the only way to get surround without using eARC over HDMI.
This has literally nothing to do with any kind of sound bar, toast0's reply to your original comment explains the situation in detail.
There is another way: decode it in your media centre and send it analogue to your amplifier. Remember when media centres were actually capable? It has to be decoded to analogue somewhere. Dolby digital and DTS are not the only way to get surround (also good stereo is better than shit surround, but let's assume you mean good surround).
The whole thing about HDMI is a circular argument. You can only use HDMI because you can only use HDMI. There's nothing technical stopping another cable supporting this stuff. That was my original point. We're in this situation for silly reasons, not technical reasons.
In 2002 there was XBMC (later renamed to Kodi). Microsoft even had Windows XP Media Centre Edition in 2005. At that time it was perfectly possible to set up a media centre that could do everything. No need for shitty TV remotes and CEC. You would use a much higher quality remote of your choice. Oh how far we've come in 20 years...