The APU is certainly not slower than a PS4, it has Zen 2 cores. The GPU might have fewer flops but it has a much newer architecture, so it could easily be faster. Just comparing flops across different architectures isn't an accurate way of determining GPU gaming performance.
Do you expect this 15W APU to be faster than full TDP Desktop AMD Ryzen 5700G? The "Fastest Integrated Graphics Ever" 13 days ago https://www.tomshardware.com/news/amd-ryzen-7-5700g-review? 5700G reaches GTX760 parity in some games like Witcher3, while in others like Overwatch its medium for APU while dedicated gpu runs same framerate at Ultra.
https://www.youtube.com/watch?v=w4z4igRnlLQ