The metaverse was never alive in the first place

I politely disagree. The metaverse is not (just) a virtual world. It's not just "the internet in VR" either.

A virtual world is just a single "verse". Only once you have many (connected) virtual worlds, you get a "multiverse". They key here is, that you can travel between these different virtual worlds, using one single avatar, one single client - and should be able to carry certain attributes and items with you, from one virtual world to the other.

To turn a "multiverse" into a "metaverse" you need to add in the real world as well. There has to be some amount of connection between those virtual worlds and the real world, with both sides influencing each other.

Just like the internet allows you to use one single browser (of your choice) to visit all kinds of different sites, connected through links. And using social logins, you are able to carry your identity (your user account) with you across multiple different sites. Combine that with the interoperability of email, where no matter what email client and email provider you use, you can send email from any server to any other server - no matter who operates them. And all of that you can do from your PC, your phone or from inside VR... And you can use it to order stuff on Amazon, order Pizza, unlock the front door of your house or turn up the heating, buy tickets to real events, or even use google maps and street-view (technically a "mirrorverse") to virtually go sight-seeing on real places across the world.

Combine all that stuff - the multi-platform-ness, the multi-provider-ness, the interoperability, the open-ness, the many virtual worlds combined with the real world - and only then are you getting close to what a metaverse would be.

And before you think that sounds awesome - also consider what an absolute privacy nightmare that would be.

Back in the late 90's early noughts it Dave Rosenthal did a research paper on what it would take to create a "stadium" with 50,000 people in it where a sporting event was held. And create the "environment" that one gets when you are actually at such a stadium.

One of the challenges is that physics does a lot of work for you, so people across the field from you talking aren't just as loud as the people behind you talking. What's more, everyone in such an event would want "good seats" but at a real event there are people all over the stadium.

You could select people in groups of 50 and put them into the same "box" of good seats, and if you built a spanning tree overlay different people "near" each other, but it is kind of like the 3 color map problem in that you're mapping 50,000 people (probably in two groups of 25,000 for "home" and "away" teams) where they can "hear" the people around them cheering/talking/Etc. Dave felt faces were impossible although these days you could train an AI model using a webcam and taking pictures of your upper body and face from different angles and have the model then generate your faces of the people "around" you.

Annunciation and site lines are pretty straight forward renders, but the actual event (assuming it was really being played by real people) would require a combination of rendering and motion capture from the real event.

The amount of network traffic going back and for in n^3 to the number of people "near" you as they form a neighbor volume.

And that is just an event where you are a passive spectator.

World of Warcraft instance servers would do dungeon raids of 40 players (in vanilla I don't know if they do that any more) and their challenge was data base updates for damage dealt, damage done, and environmental changes. Of course most of the play field is fixed for that very reason but a more realistic one that was deformable would require more physics again. We got that with the Phys-X engine and others in the early 2000's but they have yet to be able to spew what they are modelling to the other players so that everyone has the same view of what is going on around them.