Yes, a console-style desktop APU is possible.
Yes, a console-style desktop APU is possible.
Consoles typically don't rely on APUs; they use distinct GPU and CPU components. Targeting an APU console would be challenging. In the future, it might appear with a Ryzen 5 paired with an MxM laptop GPU, though likely at a higher cost than a traditional console.
The CPU and GPU are built into the same chip, not as separate components, which makes it look like an APU. Compared to the Ryzen APU, they use a custom RDNA2 GPU instead of a Vega one. If AMD had offered RDNA2-based APUs, performance might have been similar.
The main issue is limited memory bandwidth. Using dual-channel DDR4 or even DDR5 will result in much lower speeds than what a typical GPU usually needs. Achieving reasonable performance will demand modifications to the memory setup. If the system's RAM stays the same, you'd likely need a larger version of Infinity Cache, which is expensive to manufacture and probably not feasible for a cost-effective solution.
I'm sorry, I didn't understand much. You're unsure about whether the PS3 and Xbox One had separate CPUs and GPUs, but you're not sure what you think.
PS3 features distinct components: a separate CPU (cell/IBM PowerPC) and an RSX GPU (NVIDIA). PS4 and Xbox One run on x86 architecture with proprietary APUs developed by AMD, known as Jaguar, which includes a CPU similar to the one in PS3 and a Radeon HD8000 GPU.
People generally think gaming consoles should be cheaper than gaming computers.