your AORUS Gaming 5 mobo spec shows
Realtek® ALC1220 codec
Support for Sound BlasterX 720°
High Definition Audio 2/4/5.1/7.1-channel
Problem is even with a high end audio codec you can have poor audio if the manufacturer doesn't properly shield or uses poor components.
Is this true with that specific mobo you mentioned, I do not know. When you only say the sound stinks that is very subjective and can be caused by a number of things. To say the audio chip doesn't work yes it is possible that model motherboard you have not designed well with regards to audio. Or if it doesn't work then that strongly insinuates a broken motherboard... and a replacement would be just fine.
Look at any enthusiast motherboard from any other maker... asrock, asus, evga, msi. They all use Realtek. Many of the premium top of the line motherboards all use the ALC1220 codec at the moment, the other most popular was 892. While possible it could be a gigabyte problem with how they integrated audio on that specific motherboard that is purely speculation at this point with nothing else to go on.
Audio nowadays is all ruled by the realtek chip integrated on motherboards, simply check the audio specs of motherboards. If any of those does not meet your audio quality standards, however you measure that, you are then looking at a professional type audio card that plugs in via PCI-E and will all be shielded and purpose built, and not cheap, and then would likely not support your software [games].
It's just that with this board the current driver doesn't allow the software to function.
This does not mean the mobo or audio design is flawed. You need to be more forthcoming with all the information. The software that generates the audio can easily be 50% or more of the problem and would be unfair to blame it all on the audio driver / chipset / motherboard. Then there are the speakers you are using, as well as your own hearing that could be the problem.