On a more theoretical level, which configurations of the network topology can really be realised, and which ones do you recommend?

I just need help with getting a solid idea down for my paper, that asks this question:  How would you completely redesign the Internet to have a single, global routing mechanism that is centrally coordinated, yet needs to be robust in the case of failures? Can you give a high-level description of how your global network control plane would function, and justify your design choice? Here is a response to someone's idea on how they would redesign the internet to have a single, global routing mechanism. " The Metaverse is a new technology that lets users experience real life virtually. Despite security concerns, the innovative idea by Meta has the potential to revolutionize our world. It's a collaboration between partners and has interoperability across services. Virtual servers could connect to the main data center servers and allow for server overload. The Metaverse could strengthen and give access to places where the Internet is unavailable." Are there any challenges that they might…

Is it true that stub is not a kind of network topology? explain?

On a more theoretical level, which configurations of the network topology can really be realised, and which ones do you recommend?