Firearms technology has evolved heavily, since the end of World War II, across all platforms. It is debatable on whether the modernization of firearms became simpler or more complex over time. The materials have certainly changed but, due to optimizations for many different end-user aspects, it seems as if modern designs are more complex by comparison to the preceding models. The 9×18 Makarov handgun has an uncanny beauty about it and is very specifically tailored.
Everyone, within the firearms community, has a platform that first brought them into said community. The Kalashnikov platform held it for me early on. It was entirely based on an unmatched simplicity and a higher reliability than other rifle platforms available on our market. Of course, there is no such thing as the perfect machine, but the AK and its derivatives come very close. With the endeavors of American companies, followed up by the pursuits of the Russians, the Kalashnikov platform can be made as modular as any AR-15. Spetsnaz rifles started showing up with Texas Weapon Systems Dog-Leg top covers, EoTechs and UTG forward rail-integrated systems (RISs). All before the days of ZenitCo. But, they learned from what they moved out of the U.S.