With first-party isolation being the standard for the last couple of years, there are no “shared caches”. A third-party CDNs might load a particular resource fa

With first-party isolation being the standard for the last couple of years, there are no “shared caches”. A third-party CDNs might load a particular resource faster, but at the cost of user privacy & reliability. You can know, barring exceptional circumstances, that if your site loaded, it can load its own libraries. Look at the news of Cloudflare, Fastly, et al. going down and the ‘internet breaking’ because there’s been too much centralization and bad advice that all site’s need these sorts of ‘optimizations’.