I run my PC 24/7 for two reasons. I have servers to manage and I have the same exact problem as you. Intel i7-6700k on MSI Krait Z170 with GTX 1080 and Windows 10 pro. I have never gotten the computer to come back from either Sleep or Hibernation. The computer powers on and stays at a black screen. Sometimes the USB devices will power on (keyboard & mouse) sometimes they will stay dark. But the computer will always stay at a black screen. Normal power cycles (shut down) pose no problems.
An issue I have that may tie in with the problem but haven't been able to properly trouble shoot is the intel graphics drivers. I use OBS with intel QuickSync and to get that to work I must install and run the intel graphics drivers which I suspect messes up my monitor. My main monitor uses DP and every now and then it will just go black. I must power cycle the monitor to get it to come back. Disabling the iGPU in BIOS solves this problem. Switching to DVI or HDMI will also solve the problem.
Good luck, sorry for not providing much, but know that you are not alone.