The 45ACP doesn't offer real advantages.

[BlackKnight]

Originally Posted by Gatorade

A well placed 9 will have the same outcome as a well placed .40, .45, .38, .357.

Amen! I've investigated hundreds of cases of people getting shot. I've seen people getting killed from a .22 all the way up to .223 as well as shotguns. I've also seen people survive those calibers.
What I've learned is that shot placement is more important than caliber.

[DrHenley]

That said, technology has come a long way in the century-plus since the .45 was invented. Simply put, modern designs, metallurgy, hollow-points, and practicality have pushed other calibers to the fore as the “best” in a respective category.

Technology has advanced with 45 bullets too...