People depend on Chromium/Blink because there's no other options. You can't really embed Gecko, and WebKit (Safari) can sometimes lack desirable web platform features.
Even if that effort has changed focus, the community now has Rust and I don't think we've seen such a fresh language paradigm since we got Lisp, Haskell, Ocaml, F#, Scala...
In which case, the world has benefitted from browser competition as a total side-effect of competing with the incumbent browser; we got the various evolutions of C and C++. Exactly the same way we got V8 and then nodejs and the whole server-side rendering paradigm with React and JSX.
If we all fall back to Chromium for everything, then Google has achieved a Pyrrhic victory. They need a disruptor to up their game... and it isn't WASM either.
It will likely be a better engine than embedded Chromium when it's done (if for no other reason than that it seems to have fewer dependencies[0]), but I wouldn't start building an application on top of it today.
I am highly interested in finding a more performant alternative to Electron. I'm currently building a web-first game that will also be available as a fully offline native app. I'll probably use Electron unless the ecosystem changes drastically before I'm done. Some really interesting projects out there -- not just Servo, but also thin wrappers around OS web views, even a few re-implementations of CSS/HTML that just force you to cross-compile or port your Javascript to another language.
But I haven't found any that were mature enough that I felt comfortable using them. Servo was the most promising project I personally have seen so far, but it needs more time.
[0]: https://gist.github.com/flibitijibibo/b67910842ab95bb3decdf8...
https://developer.mozilla.org/en-US/docs/Mozilla/Gecko/Embed...
My understanding is that on Desktop it's much more difficult than it ideally should be.
With that said we've got a pretty solid story being worked on for mobile via GeckoView [1] and Android Components [2], there's a post on the Mozilla Hacks blog about our use of them in Focus [3] and they're also what is being used for building the "next generation" version of Firefox for Android currently code-named Fenix [4][5].
I wouldn't be surprised if there was an effort to get some of the GeckoView work back onto our desktop platforms.
[1] https://github.com/mozilla/geckoview
[2] https://github.com/mozilla-mobile/android-components
[3] https://hacks.mozilla.org/2018/09/focus-with-geckoview/
The truth is the browsers are complicated beasts these days for better or worst and so goes the complexity of building and depending on them.