The essence of business is not that anyone who can write code is guaranteed to make money. In the past, software companies made money because they possessed the ability to help enterprises complete digital/automation and solve problems. Writing code is just one way to solve problems. The vast majority of software I see today only solves the problems of its creators; they don't care or pay attention to how others' problems are solved.
Of course, you might say: "Nowadays, LLMs are so cheap that everyone can write software." But the fact is, while everyone can write software, not everyone can write a complete software. And the assumption that "everyone can write software" is currently also incorrect. Not everyone can write software.
It does however lower the barrier of entry and increases what a smaller team of developers can achieve with the same amount of resources. There's still been a major paradigm shift in our industry.
So it probably (I mean honestly I believe anything can happen at this point) doesn't mean every business will just start writing all of their own software (cheaper doesn't mean free), the bar for building your own stuff has lowered so there will for sure be more software written for internal use instead of using some off the shelf program.
And there will be more competition among software companies because everyone can now build much more with much less resources.