This reads like a paid marketing post for Cloudflare.
It's astonishing how many times the author conflates browser cache-able assets with cached assets on a CDN. When a browser downloads a static asset if the web server is configured properly those files will be cached and there won't be a need to re-download them for a very long time.
There is of course the issue with modern web frameworks like React generating a single massive js/css file that bundles everything all over again in a unique file busting all previous cached versions across all users' browsers just because a comma was added to a sentence.
Keep your js/css files small, serve them from your own web server and set a reasonable expire header, no need to pay Cloudflare $40/mo to continue gatekeeping the internet.