That's how secure random number generators work. Those are suitable for almost all purposes except for simulations, where you're tapping the RNG so often that its performance really matters and demands more than the cycles/bytes of even optimized cryptography gets you.
Plus with a simulation, you may want to replicate runs.
You can use a seeded PRNG (e.g., AES-CTR-DRBG) and get replication while still preserving cryptographic security.