Log in and check deleted or archived photo sections. This matters because photos often still exist on phones, tablets, or laptops you stopped using. Even broken devices can sometimes be recovered.
If your devices only support up to 4K at 60Hz, a "premium high-speed" HDMI cable (18Gbps, HDMI 2.0) is perfectly fine. Again, just avoid really old or thin cables. Early HDMI cables (HDMI 1.4 or older ...