Why do Windows editions on 32-bit x86 systems artificially limit RAM to 4 GB?

The article explains that 32-bit Windows editions limit RAM to 4 GB due to the 32-bit memory address space (2^32 = 4 GB). Part of this address space is reserved for hardware devices (like PCI, BIOS, etc.), leaving less than 4 GB actually usable by the operating system. This is not an artificial cap but a hardware limitation of the 32-bit x86 architecture.