“Apparently, today’s FBI has completely forgotten the April 1986 shootout in Pinecrest Florida.”
That fight was stopped with a 38 special. The death of one of the bad guys came with one of the very first shots...it just took a while. The 9mm has ample penetration, as do most rounds with modern ammo. The ammo is better now than it was 30 years ago.
Bullet placement. And no handgun has significant “stopping power”. For that, you need a rifle.