Decentralization is possible without using blockchain. Some examples of this are Diaspora and Mastodon, both of which are federated decentralized networks that do not use a blockchain.
In that case, why is there a need to use blockchain for any metaverse world, especially when the environmental reputational risks are so high? In many areas of the world, the electric grid is not decarbonized yet. The amount of power drawn for blockchain computation is high. In fact, in areas where electricity is cheap enough to draw blockchain miners, this tends to be heavily based on fossil fuels. So you could say that the blockchain is currently largely powered by coal and other fossil fuels.
So again, why bother using blockchain?
There are other examples of the buying and selling of digital property without using blockchain technology, for example domain name trading.
If we as humans are truly to be future-conscious, blockchain technology cannot be a part of our future due to its emissions-heavy nature. If we can decarbonize the electricity grid this is a possible solution (still computationally inefficient compared to other transactions), but we are not there yet. That's a bit like saying that aluminium smelters who draw lots of electricity will be eco-friendly when we decarbonize the electricity grid. This may well be true, but in the meantime you have an industry heavily dependent on use of fossil fuels and all of the emissions consequences of this.
I'm not against the trading of digital property, or against decentralization. But if we are to limit emissions then I believe we cannot in all conscience use blockchain technology as it currently stands: a technology dependent on the inefficient consumption of fossil fuels.
