I'm been in a community that makes a lot of cognitive training software. There's some core open source projects that were created without LLMs, but new projects are now mostly created by young people vibe-coding from scratch or forking and modifying the existing projects with an LLM.

The answer to your question is really obvious. The high-effort manually coded projects stick around and the low-effort vibe-coded projects are forgotten about quickly. In the end LLM-driven programming is always going to bring you to a dead-end. There's certain things where I can predict that they're going to fail because it's going to involve certain kinds of complexity they can't and will never be able to deal with. The code gets so bad that even if an expert programmer wanted to make changes it either wouldn't be possible or worth it. A lot of the time the vibecoders are so high off the low-effort sense of empowerment that they don't even realize what they made is completely broken.

Well written software has staying power because it can be understood and built upon. Understanding a problem deeply enough to devise an elegant solution even leads to new possibilities and ideas that will never be conceived with a more superficial understanding.