This is why I loved the path LG took. They used passive tech, which is the exact same tech that's used for 3D movies at the theater. This made the glasses incredibly cheap. Hell, I usually just kept the Real3D ones you get at the theater. The only disadvantage was it made the image slightly darker if you watched it on normal color/brightness. Of course, the TV bumped that up so it looked normal when viewing a movie or game.
Had everyone embraced passive, I bet it would be a feature still put into TVs today. And with HDR it would look even better.
I agree that Passive 3D was great.
Cheap, easy to use,, stable with no flicker, and you could use it with the whole family on the couch (although it does have a sweet spot range so it needed to be a comfy couch...) Passive 3D didn't allow for novel features such as "Same Screen 3D" that PlayStation TV did, but otherwise it worked/works pretty well. And Passive 3D would be significantly better today, since brightness/dynamic range, high-framerate, and ultra-high-definition display would allow much higher resolution per eye with greater brightness/contrast and at a more consistent framerate.
Passive 3D is a layer needed to be added to a TV and so unfortunately it's not something that TV manufacturers would be continuing to build into TVs now that 3D is not in demand. It's cheap for the consumer, but it's a little extra work and could conceivably affect the picture quality (though I've not heard complaints that the layer did much negative if at all.)
...However, I never understood the whole "3D is so expensive" complaint when Passive 3D started to gain popularity? The Vizio 3D TV I got was their first 3D line and I remember it being only a little more than an equivalent from the same manufacturer;
later models were the same price (though I'm not sure picture quality was always comparable.) I think consumers listed the argument about the cost of 3D because of the glasses and because all the super-high-end TVs pushed 3D, but there were plenty of bottom-feeder 3D TVs for people like me who don't buy the best and are happy with good-enough, and those 3D TVs didn't break the bank.
But, you want to know why it failed? Greed. The main problem is that almost every one tried going for active technology, which required expensive 3D glasses and, in the beginning, a separate box that linked the glasses with the TV. And those glasses had to be charged and only lasted for a few hours. It was just too expensive and complicated for the average consumer to just watch a movie.
Expensive
proprietary glasses.
Many TV manufacturers sold glasses incompatible with other TVs, meaning you couldn't just get the cheapest brand. It could have been standardized (it's just a crystal synch signal but that didn't happen (DLP had a "standard" but I assume that came with a licensing cost) and it made Active 3D even more frustrating with the costs on consumers and and inventory on stores.
If it had been standardized, it might still be a thing today. AFAIK, Active Shutter 3D is just the TV showing different pictures per frame and the glasses switching which you see when and with what eye, so if it was just a signal from the TV chipset (which is usually RF or BT, either of which TVs already use often,) any high-framerate TV should conceivably be capable of "displaying" 3D.
It might be more complicated than that, and also precision matters greatly, but with the ever-increasing processor power inside TVs for other features, it seems like that should have been doable. Projectors often have 3D, and they're less picky now about manufacturers, but I don't love Active 3D (it's a very cool idea and it can do some things that Passive can't, but even with UHD and HFR TVs it'd still have some drawbacks today,) but if it's essentially freely doable, you'd think some manufacturer would just do it.
Unfortunately, doable or not, no TV manufacturer does it.
Slightly related: I remain surprised/annoyed that there isn't a major "3D Cinema" app on Quest with buy-in from major studios, so that you could easily rent and watch recent major 3D theatrical releases (and trailers) on a virtual screen without having to connect a PC or go through any extra hoops.
There was, I believe, back in the Gear VR and Rift days, but it never took off on Quest for whatever reason. Fandango Now and Vudu had 3D movies, but the selection was not great and you had to buy them in that format; Meta also for some reason changed its video streaming function and it seems those apps don't work the same anymore. (
Netflix has some 3D movies but I don't know if it works with Quest?)
Nintendo 3DS had some 3D movies available through eShop if I remember right. Those are gone, but you can rip 3D content and convert it to a 3DS format. I never tried that but I'm interested in how that worked out?