An unchambered gun might as well not be loaded. I used to carry that way. In a situation where you are confronted with an attacker you may not be able to pull the slide. Also, if your hands are slick or sweaty in any way the slide will slip. I don’t have a Glock - my Rugers have actual safeties that I use.
“...where you are confronted with an attacker you may not be able to pull the slide. Also, if your hands are slick or sweaty in any way the slide will slip..”
Most certainly that argument can be legitimately made. Personally I don’t anticipate a quick draw throwdown nor drawing on a gun pointed at me. I try and anticipate a situation and do what needs to be done at the appropriate time. I love my pinned and recessed old school S & W revolvers but there is no way I would carry them around eared back....which is essentially what Glocks are give or take 2 or 3 pounds trigger pull. I admit that Glocks are fascinating.