Earlier quoted context omitted.
It's fine if you don't want to call it a waste of bandwidth, but bandwidth is definitely still used because browsers don't share caches between domains https://www.stefanjudis.com/notes/say-goodbye-to-resource-ca... .
Silly point as jQuery is a few kilobytes meanwhile your custom font is a few megs.
It's a reasonable argument to make that minimizing 3rd-party library use is premature optimization for most websites, but if you get to the point where you need that optimization then it is 30kb and it won't be cached (CDN caching is a myth, CDNs are only useful for minimizing server load/response-time they aren't shared between domains) and it will block your initial app logic.