Glocks have been in use by several elite US military units for some time. The US Marines MARSOC issue the Glock as their duty sidearm. Since 2015. Designation 'M-007'. Pretty wise choice, as you can't go wrong with having 17-20 rounds of 9mm on your calf ready at a second's notice during the heat of a firefight.
It might "make sense" but that's not how US govt procurement works.
If the total procurement cost is $$$$$$$, then picking a gun that's
"low cost firearms that go bang all the time and if one needs repair it's relatively easy to fix. they are both combat accurate" is only part of the acquisition calculus.
Historically, governments have had a tendency of being behind the times. Always. For some reason, decision-makers who are removed from the front lines and give orders exclusively from climate-controlled rooms and big wooden desks always have the tendency to go the route of "I am right...You don't know anything.......I know what is best".
In 1863, the US Department of Ordnance had two handguns to choose as their official sidearm: The Colt 1860 revolver or the Remington Model 1858. The Ordnance Dept. went with the Colt, even though front line officers and soldiers, frontier scouts, law enforcement officials, prison guards, private security contractors, and many others all attested to the Remington being far more rugged and reliable than the Colt. And the Remington was cheaper than the Colt, by the difference of 9 cents per gun, which during that time was a hell of a big deal. Yet, the Army went with the Colt. Simply because Samuel Colt himself has a private audience with the President and the Patent Dept. And as a stroke of marketing genius, Colt was known to present senators and Ordnance Dept. guys with cased sets of engraved revolvers. Colt won the approval simply because they were better advertisers and the government liked a lot of bling and sparkles.
Remington Arms Co. on the other hand? They were only concerned about making products that work. The Model 1858 New Army (actually, to be historically accurate, it is the Model 1863) was the Glock of it's day. It ain't pretty, but it is built to get the job done. Many privately funded units in the Union Army, like the Chicago Board of Trade Independent Battery Light Artillery, issued Remingtons to their troops, because they tend to be more closer to the grit and grime of the action and they know what kind of tools work best for the job they are doing.