That’s the whole quantity transforming into quality thing. Problems often build up over time, and they’re not visible on the surface because the system is able to amortize them internally. So, it can look like nothing is visibly happening, but then once the existing stocks become depleted and it’s no longer possible to amortize the problems, big events like economic crashes occur seemingly out of nowhere. A great book on the whole thing I can highly recommend https://research.fit.edu/media/site-specific/researchfitedu/coast-climate-adaptation-library/climate-communications/psychology-amp-behavior/Meadows-2008.-Thinking-in-Systems.pdf