you're right, but flipped on its' head it also means that a well-meaning FOSS project may not ship out a zero-day in the future that affects half the planet at once.
now we'll just always be vulnerable from different angles in different and unique ways across the globe.
better? well, no.. but it is different, and biology has offered tons of wisdom about why it's a good thing to achieve things different ways across the world, maybe some far-future version of this weird fragmentation of work that is happening now will contribute to some kind of herd effect that reduces the severity or magnitude of some bug or work of malice.
who knows though, i'm probably just considering it too positively. The disintegration of consolidated effort is a pita, I agree.
There has to be a middle ground between a monoculture and not sharing a single knowledge bit between every human. Because if everyone is making their half assed thing just for themselves using LLM without sharing anything, that also means FOSS will stop existing, and knowledge will only evolve inside the corporations that have money for creating their provate knowledge bases.