Well, these libraries are doing something inherently complicated on top of just using browser cache headers. You're only talking about http endpoint caching. T

Well, these libraries are doing something inherently complicated on top of just using browser cache headers. You're only talking about http endpoint caching. These solutions are providing application data caching. These are not mutually exclusive concepts. The latter offers things like data sharing/normalization across endpoints, data persistence across browser sessions, fine-grained cache invalidation/manipulation, and a lot of things on top of that. It's a lot harder to manage a cache, and for most apps I never found it worthwhile. But there may be cases where you do want that level of control, like PWAs or an app optimized to never hit the network unnecessarily. But it's definitely not replaceable with browser http header caching.