I’m not sure there would’ve been any way Sony could’ve managed backwards compatibility with the PS3 on the PS4, short of building a PS3 into the PS4, given the

I’m not sure there would’ve been any way Sony could’ve managed backwards compatibility with the PS3 on the PS4, short of building a PS3 into the PS4, given the vast architectural differences between the two. It’s only been in the past few years that x86 PCs have become powerful enough to emulate the PS3 well, and I have serious doubts that the Jaguar APU in the PS4 had anywhere near the raw horsepower required to emulate a PS3. By contrast the Xbox 360 was built with a relatively simple tri-core PPC G5 which mapped to the hardware of the hardware of the Xbox One much better. The OG Xbox was just a Pentium III PC which no doubt made backwards compatibility with it much simpler (just need to virtualize an Xbox). Microsoft has also had its own share of consumer unfriendliness, like the ridiculously expensive WiFi dongle for the 360 or how the current gen Xbox uses a proprietary expansion card slot for storage upgrades (contrasted with the PS5 which just needs a mid-to-high spec NVMe SSD like you’d put in a PC).