The sad truth is, some companies will look at Statcounter[0] and say because Firefox does not reach 5% global population and decided not supporting it, actively or passively.
In this case, there's also people from Mozilla onboard, so there's no guarantee that it'll remain chrome only or that chrome will keep it if the spec doesn't go anywhere.
In fact, much of the web as we know it evolved this way. We have IE to thank for AJAX, after all.
[0]: https://developer.chrome.com/docs/web-platform/element-captu...
[1]: https://developer.chrome.com/docs/web-platform/document-pict...
But QUIC significantly increases CPU utilization on servers, at least the widely used userland stacks do. Unless/until Google deploys QUIC in the kernel (or puts the whole network stack in userland, a la DPDK), this won't change.
The multicast claim is kinda bizarre. I can see how QUIC could help eliminate UDP client barriers, but those barriers pale in comparison to multicast. Multicast routing just doesn't exist on the Internet; it's only supported within some independent, typically small networks. Most ISPs don't support it. Wherever you could manage to distribute content with multicast, you'd necessarily also be resolving the collateral routing problems which QUIC support resolves, whereas even ubiquitous QUIC doesn't materially improve the multicast situation.
In my opinion, QUIC and HTTP/3 are technical marvels, but are perhaps way too complicated and don't really serve the interest of most internet users.
There will be a point in the development of web browsers and associated technologies where we should just stop a bit to get things stable instead of churning protocol version after protocol version after new API. Will it ever stop?
Eventually, it all becomes so complicated no company can manage it all. Honestly, we might already be past this point, with Chromium at almost 40mi LOC, more than the Linux kernel itself, including all its drivers. When will the madness stop? Do we really need such complicated software to see Instagram posts, comment on a few Hacker News threads and mess around with Google Sheets?
The biggest reason I worry so much about this is that in the web, adding new features, APIs and protocols is easy. Removing and deprecating is basically impossible.
[0]: https://github.com/mozilla/standards-positions/issues/1288
[0]: https://developer.mozilla.org/en-US/docs/Web/API/HTMLGeoloca...
[1]: https://mdn.github.io/dom-examples/geolocation-element/basic... (requires Chromium)