CZ 75 and 1911 are old school guns, made out of machined steel.
Anybody with the machine tools (and maybe a hot line to the Indian MIM contractors) can build one.
The "modern" guns call for specialized heavy industry.
Sure, it is cheap to mold a plastic receiver, once you have the molds and high pressure injection systems, and the stamping presses to make the metal inserts and working parts. But those are not cheap or simple or standard equipment.
Consider the AK47. Everybody looks for the milled AK without realizing that the gun was designed to be stamped. The only reason there are milled AKs is that there were a lot of unoccupied milling machines and machinists as they changed from MNs and SKSs so they put them to work while they got the big presses and learned to use them. Eventually the AK was made the way ol Mikhail meant.