... what is the point of Pseudo Random Number Generators?

There are monks about the place far better qualified than I to answer this, but I thought that the repeatability of a PRNG was one of its main attractions. From the vast array of well-studied PRNGs, there will be one that can satisfy your entropic needs, and if you're running, say, a unit test, specifing the same seed on each test run always produces the same sequence of test input values.