I own quite a few 1911s, CZ, etc pistols. Only had two Glocks, a gen 3 and a gen 4 in 40S&W.
The Glocks (in my hands) shot almost as well as my 1911s. The current one has adjustable sights and a slicked up trigger. I seldom shoot the Glock, so the trigger does not feel natural to me. I am sure that if I shot it as much as a 1911 the group would be about the same.
I test by shooting two-handed at 20 yards. I consider a pistol accurate if I can shoot a group that would fit in the black of a bullseye target. Just about every pistol has been fitted with adjustable sights and a trigger job.
The other part of the equation, and I mention it because I think many shooters don't know or believe this, is that I develop a load for each pistol. My handloads go into tupperware containers, and the label shows the load data and which pistols it is suitable for. If you only have one 9mm, etc, then you only need to develop one load.
I start with a bullet that will probably be good and then load it in 0.3 gr increments with 3 different good powders. Some groups were huge and one or two would shoot tight clusters. Shooters who do not handload and develop their own load are at a big disadvantage, I think.
Here is a Norinco 9mm I bought on EE for $150. I smoothed the sear with some lapping compound and developed a load. I can get a similar group with my Glock 22.
This is a Para-Ordnance 12-45 I don't think it needed a trigger job or any mechanical tuning. From my limited exposure to a Glock, the Glock will shoot as well, but I have to try harder because I don't care for the mushy trigger.
Edit: just found a Glock group picture.