I think it is a nice thought experiment but exactly Oberon project shows that even a few smart people really can't be expected to create useful solutions. Have you seen the filesystem? It's been a really long time for me when I looked at it but as far as I recall you had to create a partition for each directory, essentially forcing you to anticipate the size of each directory you create. So, yes, it's a nice system to run in a virtual machine, you can learn a lot about how an OS is built. As for useful... not really.
If we had lots and lots of really smart people working on a new version of everything, though, my guess is that we would end up with pretty much the same stuff we have today. As another commenter said, a lot of software projects doing next gen rewrites from scratch fail. The reason is simple: they focus on solving painpoints and forget about the areas that were neatly addressed by the previous architecture.
The best approach IMO is to address the painpoints by refactoring them properly into the architecture. That is often very complex on its own but still has the best chance of succeeding.
If we had lots and lots of really smart people working on a new version of everything, though, my guess is that we would end up with pretty much the same stuff we have today. As another commenter said, a lot of software projects doing next gen rewrites from scratch fail. The reason is simple: they focus on solving painpoints and forget about the areas that were neatly addressed by the previous architecture.
The best approach IMO is to address the painpoints by refactoring them properly into the architecture. That is often very complex on its own but still has the best chance of succeeding.