Did we though? Can you point out some books, or PHDs or whatever slightly more scientific and substantial than blog-post anecdotes?
I honestly believe as an industry we completely don't know how to scale development and I would love to read something that helps understanding this challenge.
But I'm just thinking of something like the transition from BASIC to Pascal (which I experienced in 1983). There were rules of thumb that we learned in BASIC (avoid global variables and GOTO's) that were formalized in Pascal, and Pascal also let you create much more elaborate named structures, and control the scope of names more precisely.
That's just one really simplistic example, but it rather profoundly improved my programming. On the other hand, I can believe that scaling is still a struggle -- there is still a point where we run out of juice, but it's a lot further than you'd get with BASIC, or with Excel-sans-macros.
Some take these things more seriously than others though.
But here's what I think you give up if you don't have code. Over the past 70 years, one of the problems that computer science has studied is how to manage the size and complexity of programs and development teams. This complexity includes not just the program you're working on, but potentially the entire ecosystem of algorithms and solutions available for your use. Nothing comes close to "code" for addressing this problem.
As a result, I think if you're going to give up code, you have to accept that your projects will run out juice if they get too big or complex, or that you will have to solve some interface problems with manual steps. That might be perfectly OK.