Minecraft is great but to my knowledge you can't make a portal in one Minecraft world to another world, you can't take an object from one Minecraft world to another world, and you can't transit from one simulation to another simulation (all Minecraft worlds run the same simulation: the Minecraft simulation). It's not really a metaverse in that it's not one connected uncoordinated space, it's many separate, instanced…
I feel like taking an object from one simulation to another and having different simulations are oposites. Either you have the same simulations and thus objects share behavior, or the simulations are different and the objects are just 3D things.
not really, we just have to get into some semiotics here and consider the difference between the signifier and the signified (https://en.wikipedia.org/wiki/Signified_and_signifier). In semiotics, a signifier is a physical artifact; the manifestation of something. A physical stop sign, for example. The signified is the concept embodied by a signifier. All of the stop signs in the world correspond to (roughly) the same concept of stopping, but they are separate instances of that concept. Separate signifiers (instances of "stop sign"), all with the same thing signified (the idea that you should stop).
Now in games, we have the notion of the signifier and the signified, too. Let's take an example item from WoW. I'm using this as an example because it's a game I'm familiar with. An item like Staff of Westfall (https://classic.wowhead.com/item=2042/staff-of-westfall) expresses several things. The first thing that it expresses is that it's a weapon so it uses your weapon slot to equip it, and the stat bonus of +5 intellect that gives you additional mana and +11 spirit that gives you mana regeneration. Great, that's nice. Those things can be taken to be the content of the item: its in-simulation properties and effects. But what does the existence of this item signify? The Staff of Westfall can only be obtained by each player exactly once, cannot be traded between players, and can only be obtained by going to The Deadmines, a particular dungeon, and defeating the final boss. Equipping the Staff of Westfall has the effect that it gives you mana and mana regen, but it also communicates something non-mechanical: that the player carrying the Staff of Westfall has gone to the Deadmines and fought and beaten Edwin VanCleef.
Now, can the Staff of Westfall be transferred to another simulation? Yes and no. The signifier, the physical (virtual?) staff can be transferred to another game in some sense. The 3D model can be transferred, the physical appearance of the item can be transferred. But that was always on your computer all along; it's not particularly meaningful. The effects of the item may or may not be transferable; if a game is not the exact simulation that WoW is, what does +5 intellect and +11 spirit mean? The game operator may elect to translate that to some other concept in their game, or they may not. I think this notion of "transfer" is what you're eluding to: the transfer of the signifier. This concept is probably very useless. It's also the concept that people are generally talking about when they talk about the transfer of items between games. I think it has no merit at all.
But there's something else that can be transferred: the thing that ownership of the Staff of Westfall signifies: the concept that the person holding that item has slayed Edwin VanCleef (in WoW). Transferring the Staff of Westfall may not mean transferring the physical model or its attributes, but it may mean something more along the lines of transferring the meaning of what the player has accomplished. Admittedly, I'm not sure why this would be useful or what the applications of such a system would be; what I'm getting at instead is the idea that transferring an asset may mean many things, and that transferring an asset from one simulation to another is not necessarily the opposite.