Neither software nor architecture are easy to understand.

The wall example is similar to "Write a simple calculator capable of doing addition, substraction, division and multiplication". Anyone can tell if that software works as expected or not and have some idea if it's well done or not.

A similar comparison would be a team designing and building a fully functional house on a budget. In that example it's not easy at all to assert how well they are working, as happens in software development.

I think a software developer is more like a carpenter (and sysadmins are like plumbers, and electricians are like devops etc). I assisted in laying a 150m2 hardwood floor from a 40 year old warehouse earlier this year. There were quite a few invisible processes that were required to get the floor right. And it wasn't clear at the start that the job would be successful. But because of a very skilled carpenter, and my dedication in doing lots of prep work for him (cleaning, grading and flipping the boards) we got a result that cost the same as new boards[1] and looks amazing, and will last another half a century at least.

[1] only because I got the boards for wholesale price.

I don't think it's nearly so hard to understand.

Does the software solve your problem? Then it's good software. If not, then what are you paying the programmers for, anyway?

But some problems can be solved in a day, others require an immense amount of work. Not everybody can tell the difference.