I'm really not worried about this scenario at all. I mean yes, it will be possible for bad programmers to build 173 million line monstrosities held together with duct tape and bailing wire, and certainly these things will exist. And it's also possible that good programmers will be paid by idiots to maintain said monstrosities with no agency to actually fix the root cause. Both of those things will happen.

But a good programmer given agency to solve the higher order problem will always have a path to rewrite, because any "simple CRUD app" exists to serve human purposes, and in order to meet those needs the human interface need to be legible, and to be legible there have to be tight enough inputs and outputs that you can create a parallel implementation without the incidental complexity.

Now you might say this won't be the case for large multi-party distributed systems, and that is true, but that is also true today where all manner of insane cruft and non-sensical logic and workflows exist. But even where things appear totally intractable due to legacy requirements and conflicting logic, there still is a human backstop where if the pain is big enough, any process can be fixed. In practice competing interests may prevent such fixes for a long time, but that is political problem not a technical problem, and it's not inevitable as things can flip very quickly due to the dynamics of human attention and power.