It's not a "mix." Sharia causes those things. All Sharia-compliant societies will eventually have the problems you describe, no matter how they start. This has been demonstrated time and time again in Islamic history. Islam moves into an area and takes over the existing society, which is sometimes very good. Then Islam slowly breaks down society to where it is garbage and the Muslims flee to new areas and start the process over and/or abandon sharia, which eventually leads to calls for "reform" as society improves.
Sharia/proper Islam causes the problems. It is not simply "mixed" with the problems accidentally.
When you talk about Shariah law among non Muslims, they quickly make reference to Iraq, Iran, Afghanistan, Northern Nigeria and all those places.
But those are places where Shariah has been mixed with poverty, abuse of women and children, child marriage, oppressive governments, blasphemy killings and more.
So how do you convince them that Shariah is a perfect legal system when, in their eyes, it has brought nothing but pain and oppression to nations that practice it?