The PS3 was built around a custom PowerPC processor called Cell, which was also used in a supercomputer developed by IBM (along with Sony and Toshiba, they formed the alliance that developed Cell). PowerPC is, of course, the same instruction set architecture Macs used before the switch to Intel (and the subsequent switch to ARM-based Apple silicon).
The Xbox 360 was also based on a custom PowerPC processor. Its successors, as well as the PS4, PS5, Steam Deck and several Steam Deck-likes, are based on AMD SoCs - some custom, some off the shelf - that are functionally no different from what you would find in mainstream laptops. They're basically PCs.
On the Nintendo side, they too used custom PowerPC processors from the GameCube through to the Wii U. Their handhelds were all low-powered, ARM-based chips - the Switch is a much nicer, NVidia-provided Tegra X1 (X1+ in newer models). As we know, ARM's instruction set architecture is under the hood in every device Apple sells now - the A series chips and their more powerful M series siblings. If a Mac is a "PC", a Switch is basically a PC.
This is all a dramatic oversimplification, but phones, tablets, laptops, desktops and games consoles all share a tremendous amount of DNA now. Whether it's their hardware architecture, the fact many games consoles run modified versions of Linux, or the overlap in tasks they perform. The differences are increasingly arbitrary based on intended use. For that reason, if the App Store needs to be broken up, so do the games consoles' respective digital marketplaces.