VC backed for profit engine is precisely what Unity is though?
So is Unreal and CryEngine.
Both of which only survive on graphical fidelity, which is not what Unity was touted for.
Unity was for filling that small-to-medium sized games in terms of man power, if you got 15 years of experience then you should know that.
I think it would be more interesting to see a Coop backed engine, where the COOP has to listen to it's customers.
Since my biggest annoyance with proprietary software or in this case game engine is that you can create the most elaborate sub-engine (for example a fully-dynamic RPG) and see it all come crashing down because some dimwit at Epic Games reeeeally wants to push the latest eye candy that breaks your sub-engine.
That's the one thing OSS is far superior at, you can fork the engine form a new developer community or even work with the OG maintainers to incorporate the sub-engine as a module and as such be officially supported both by your team and theirs.
Meanwhile with proprietary software, you're stuck at this particular version with no legal way of ensure the survival of the project, RPGMaker games are the perfect example of this, as soon as you venture past it's originally intended fidelity, you're essentially going to be limited by the engine in terms of performance.