Traditionally, american made firearms need to be broken in before they function properly. You don’t need to break in a glock. Glocks have such loose chambers that they generally work no matter what.
I bought it for one reason and one reason only - dependability. Most naysayers here and elsewhere are biased for whatever reason, usually one bad experience, or a few related bad experiences from people that limp wristed, had a poorly maintained weapon, or just simply got a bad item (it happens with everything).
My Glock seems to be pretty darned tight in all aspects, but I don’t have much to go on other than my father’s 9mm.