Or, digital encoding on vinyl? Pretty low bitrate, but... They already do this a bit for DJing - the vinyl they are "spinning" is usually just a bunch of position indicators so the software can reproduce the motion from a digital audio file.

Lol.. other than the one side part (turtle anyone?) what you're proposing is a laserdisc. Ie an actual thing. They're not coming back either because they died. Vinyl never died it just declined. Simplicity of playback equipment is a big reason why. Also nothing stops anyone from putting a CD in a 12 inch jewel case or sleeve of some sort.

Why start another format? People will either have to re-buy stuff or they won't care. One great thing about vinyl is you can get old records on eBay for less than £5. Start a new format and you lose that. You would also need to re-release a lot of stuff (which isn't going to happen).

Phillips already experimented with an audio laserdisc in the late 1970s.

It requires the audio to be modulated (using FM) and thus this introduces serious barriers to the sound quality.

On the LP, the audio is baseband. It isn't modulated at all.

You can already buy a laser player (http://elpj.com)

Because part of what they are selling is nostalgia, so making it into something 'new' is counterproductive.

Don't you get it? This class of audiofoolery actually values the imperfections of obsolete tech.