Only cryptographers care about "unpredictability." Outside of cryptography, the interesting properties of a PRNG are speed, period length, and state size.
But a good CSPRNG has excellent statistical properties. So if you make "unpredictability" a requirement, their slow PRNG becomes very attractive. In other words, they made up a problem for their solution.
If you need a statistical PRNG, use a statistical PRNG. (The best are xorshift1024* and xorshift128+.) If you need a CSPRNG, use a CSPRNG.
But a good CSPRNG has excellent statistical properties. So if you make "unpredictability" a requirement, their slow PRNG becomes very attractive. In other words, they made up a problem for their solution.
If you need a statistical PRNG, use a statistical PRNG. (The best are xorshift1024* and xorshift128+.) If you need a CSPRNG, use a CSPRNG.