Of all of these, DNS is the easist to address --
anyone can set up their own forarding nameserver pointing at the roots. Performance is pretty good.
Much as I distrust Google for anything these days, 8.8.8.8 / 8.8.4.4 offer a widespread advanced notice of domains tracking up the hit rates, and possible attacks.
Email, as STMP, after decades of nobel service really simply does deserve to die. It's far less about the mechanics of email user interfaces, for which there's a great deal of ink wasted, and much more on privacy -- encryption, metadata, and spam, probably as the three top concerns. Very nearly all the suggested replacements (SMS, various messaging systems, Facebook) have either those problems or those and the fatal condition of being proprietary silos.
The more I reflect on it the more the Web is close to what Usenet was, at least in some regards. Origins post messages, which may or may not die in short order (what's TTL for an Internet page now, a few months on average?). We're increasingly relying on sites such as the Internet Archive to actually provide a view-through-time at content.
What the web (and email, especially in mailing lists) lacks and has always lacked is a requirement to meet standards conformance. DDG "The Web is an error condition" and you'll find a far-too-true-to-be-good rant on that topic.
The loose-standards-anything-will-fly-nearly approach has allowed a great deal of flexibility in page design, but much of that is ultimately painful. I'm finding a much greater appreciation for straight-up HTML 1.0 formatted pages.
A huge part of the problem is exceptionally crappy entity styling defaults. If browsers presented pages sanely (at various resolutions), much of the B-Arc profession of Web design would simply cease to exist. And this would be a wonderful thing.
A simplified markup, acceptance criteria (and rejections for failed formats), cache-and-foreard, client-determined-formatting, security, and either a universal content syndication or UBI type compensation model might address other issues.
I'm getting the sense of some interesting possiblities out there.