I wouldn't say that the modern firearms are sloppy. They are just manufactured differently to safe cost. Take for example a small sidearm like the current Glock model 27, which has a plastic body, and bare minimum metal with the firing mechanism in the slide, comparing it with the all metal Walther PP, which has that distinct look and finish of the earlier era production. The difference is huge.
Other than the frame being polymer vs a machined steel, the design of the slide, the striker mechanism... it was all meant to reduce machine and assembly time and to reduce weight and complexity. Does that make the Glock a "sloppy" pistol compared to the PP? No, just one that doesn't give snobs the good vibrations from owning a pistol that has a distinct look and steel frame.
In regards to the topic, I feel we've reached the climax for semi auto pistols in terms of their function and build materials as pretty much every semi auto pistol is the same, it's just a matter of how much you care about longevity, parts availability, and customer service.
That's not to say a Taurus G3 is in the same league as an HK USP, it's not, but I expect the G3 to protect me just as well as the USP will. After 10k rounds however... I'm not so sure.
Most people buying guns will never put more than 1000 thru one gun over its life, so the need for a gun to last 10k rounds is minimal.
Where I do see sloppiness with firearms is in revolvers and that's because the amount of machining they require is astronomical compared to semi autos and that added time creates added cost that few are willing to pay for a low capacity, slow reloading handgun.
I won't touch rifles, all the diehard gun nuts on forums want is wood and blued steel and what moves in the marketplace is polymer and aluminum.