Glock and CZ have done extensive testing with their guns over the years. I am not going to start googling articles, but CZ actually has their testing procedures on their website, >less than .05 percent failures in 5000 rounds, "or something close to that".
I from my own experiences with hundreds of handguns over 45 years of carrying, have never felt more comfortable as with a Glock in the holster.
I enjoy shooting many other guns more, but for reliability sake I never ever had one fail in any way on me. No FTE, FTF, failure to go into battery or any other malfunction that could stop me from breathing. If anything can be said for them they don't do everything the best, they just do everything every time you require it.
I have left Glock mags loaded for 15 years, and put them in a new pistol, and they worked as well as if I just loaded them up. I really cannot say that about any other gun I own, even if it were true, I don't have them long enough to know if they would be as reliable.
My nightstand gun is a 30, and my go to is a 26, and I may carry a Kahr pm9 or an XDS, at times, also they have never failed to fire, but just don't have the time in. I would not expect a 1911 to do the same if not occasionally checked and have routine maintenance performed on it, "but it may as well do the same". I just know the Glock will fire from my past experiences, as much as anyone can be sure of anything.
Understand that anything can break, we are just looking for the least likely to break in the longest amount of time.