Software moats were never really a moat in and of themselves. You always had to be a first mover. It's true that there are fewer and fewer first mover opportunities, but that has less to do with recent LLMs advancements and more that we have already solved a lot of software problems on first principles. It's partially why LLMs work so well, they are pulling the "widgets" from distribution and synthesizing into your requirements. Before, we probably thought we were writing novelty when it was literally solved 1000x over.

If you aren't a first mover, your success was always dependent on other skills and great execution across multiple disciplines, and also a lot of stubbornness. The software layer has always been important, but a support role of successful enterprises. Start-ups have always been hard to pull together successfully for a lot of other reasons unrelated to code.

If you find a disruptive algorithm (like pagerank) there is little evidence that LLMs will infer your solution by looking at your app. Anything else, they are just design choices and have never been moats either, but say you have a qualitative edge, you'll make the choices that can create a recognizable brand where someone vibing a copycat may not care as much. Nothing has changed on this. Your chance of succeeding rests on your ability to reach your users and iterate in a crowded space, this is what you always had to do anyway.

There are things, however, that aren't worth working on anymore with the advent of LLMs. Some of these have been fully dismissed, for example sentiment analysis. A single API call for the cheapest (even local) LLM vendor will give you SOTA classification. There are many more examples but they are so obvious. Essentially, the "build me 1 billion dollar app" prompt will never work, so if you have a burning desire to build something, do it. Just remember, there never was and never will be a promise of unlimited fortunes whatever you do.