[colordrops]

In most cases I believe time estimates for technological advance to be far too short, but in this case I believe the estimate to be far too long. We've already got decent 3d engines running in the browser - it's not theoretical. With the current pace of web tech advancement and the advent of web assembly, it could easily happen within five years.

[stcredzero]

In terms of presentation, you're dead on. In terms of tooling and development environment, not sure that that's going to be.