I know it sounds like a weird thing to say. But had you as a customer demanded and were willing to pay for something different, you would get that.
Think about how the public sector buys a software development project; what the sort of process the supplier has to go through, how they qualify, how they bid, how the requirements are formed, how the software is tested, delivered and so on.
Had the public sector prioritised the internal quality; it could have done so. But it chooses not to.
In a public sector IT project the actual softare development is only small fraction of the cost. Other parts. Sales, legal, management, testing, documentation ... have much bigger impact on the suppliers ability to make money. Thus those are the parts you get and that is what drives the cost.