Until the recent overall shortage one advantage was widespread availability of broad variety of cartridges to cover just about any purpose to which the 308 is suited. The general shooting public isn't as dense with handloaders as is the population of this site.
Just about any short action rifle is regularly chambered in 308.
The widest variety of off the shelf reloading dies include the 308 in the lowest price tier for the given type of die.
The best brass becomes available in 308 before many other cartridges.
