Was Bill Miller a value investor? , the guy who founded Miller Value Investors? I remember him loading up on Amazon when the rest of us were scratching our heads.
So your statement that value investors didn't invest in internet stocks isn't quite correct. Amazon was considered an internet stock. Miller saw the potential and felt he could intelligently value those future cash flows. To say value Investors don't invest in XYZ business is a demonstration of a lack of understanding of what exactly value investors do.
A value investor will invest in anything cheaper than its value (however they access it). The fact they don't invest in something is a matter of them not being able to value it or it being fully or over valued - and all these assessments, if properly undertaken, employ some manner of risk assessment which Buffett managed by seeking a significant Margin of Safety in his valuations.
As for your statement that there is always something better than cash. To say that, you would have to have a circle of competence large enough to value all possible investments.
I don't thing I'm smart enough. Maybe you are.
But I take comfort that I can recognize the limits of my intellect. At least sometimes anyhow..
A Genius is a Man who knows he is not one. (attributed to Einstein - I heard Warren quote this once)