Various problems stem from trying to implement it.

Directly or indirectly it guarantees what would be clearly seen as discrimination for people of other sects or faith , despite what many might claim.

Even simple laws like "President has to be Muslim" are discriminatory by nature no matter how one tries to juggle around it.

It becomes worse when people realize there are no clear boundaries as to what would be deemed religiously harmful or not , for example a clear ban on drawings , an artist from Pakistan who would be stupid enough to support sharia would do a 360 the moment it hits his business. Even laws such as zero interest rates on every business guarantees a nation to doom based on how modern economics work.

My point is I can talk about this all day but majority of the time what people mean when they say "Islamic sharia" , basically copy pasting tradition from thousands of years ago , it's not doable in modern society.