A local cache helps with performance issues but you still need to get it from somewhere, which means you’re still hoping someone else has dealt with those issues, not to mention the cost of maintaining a high-quality robust local server.
I’ve seen this cycle with Linux distributions, Java, and Python packages (arguably even Git), and several digital preservation systems (I work at a library so this is a popular topic) and each time there either ended up being strong user demand to switch to the performance/stability/consistency of a centralized service, that happening de-facto with one or two big players doing most of the work, or falling apart because the contributed resources were insufficient. Getting the incentives aligned for something like this is really tricky.
