You can start building the Metaverse now!
No need to reinvent the wheel. Take advantage of the thousands and thousands of tools already built for the web.
The metaverse will be there whenever you'd like to go into it. It doesn't matter where you are or on what device (Disclaimer: Web Metaverse doesn't yet work on Mars).
No one owns the Web Metaverse. As long as you can host a server, you can share your content with the rest of us. Being protocol-based, the Web Metaverse won't lock you into any one platform.