This has always been Intel’s approach. As an example: these are modern CPUs with integrated Intel Iris Xe. All of them support DX12.1 yet none has any vRAM whatsoever. They all use / share system RAM. It’s still good enough to play GTAV on medium @anonymous_user_f8e33caa1 fps. Not bad for something as small as one’s fingernail.
There’s usually a generational gap between DDR RAM. If your OS runs DDR4, it’s likely that the beefy GPU needs GDDR5/6 at this point. Using slow system RAM where bandwidth is really needed has significant performance implications. But it’s actually not too bad since those tiny chips are underpowered anyway and no one expects them to run fast.
Extra reading in case someone gets excited by random access memory in general 