Solution spaces for even seemingly simple problems is incredibly large. There's a reason there's a thousand different types of nails and a million types of screw heads. Just making every screw head Phillips (or pick another) doesn't just make things work.
But you need expertise to know these things. They're the issues that are subtle and appear to work but you end up breaking things (often invisibly) and just end up chasing problem after problem. It looks like a new problem but it's rooted in something else.
