Applications of Transistors with Different β values

Usually variation in B is due to optimizing some other variable. For example maybe you want to make a transistor that can carry a lot of collector current relative to other transistors, a very low temp co, or have a really high Vce breakdown voltage, etc.. These optimizations usually come with reduced B.

One can also sacrifice on the other variables of a transistor to maximize B. This is often done with low power (Ic<100mA) switches. Because of the high B one can manipulate Ic with very small amounts of power in Ib which is useful for switches.