This opinion should only come from a CS grad who is accustomed to building CRUD apps and allergic to any real world problem domain.
At my work in insurance solutions we're solving perabyte scale problems. We do not have a Rust developer in the team, but taught ourselves with the AI and now automating workflows which took days to under a minute now.
If you look at the speed a company rolls out new products/features, it should be obvious that "interesting ideas" especially good ones are infrequent and rare.
No offense, "using Rust to address a performance problem" is by no means novel or interesting. That is just another person's CRUD.
Using Rust is actually the most boring part of the problem. It would be almost impossible to solve for anyone without certain level of domain expertise.
VR and virtual worlds have been explored for decades, both in fiction and in the real world. The issue has always been that the target market is small. I don't know how Meta does market study, but the conclusion was already foreseen.
But the realm of what you can do with a computer is huge and working on the web is a very small part of it. Some other interesting part (for me) are OS development, network communication, computer architecture, embedded hardware and programming languages.
I am not Meta, neither are you, nor are we doing things on their level. You can just build small things for you and your friends that fits your specific usecase that other tools do not fit yet, it doesn't need to be a world changing idea.
At my work in insurance solutions we're solving perabyte scale problems. We do not have a Rust developer in the team, but taught ourselves with the AI and now automating workflows which took days to under a minute now.