Is it just me or the graph at the end of the article is not really showing rising adoption in general. It basically shows a couple of spikes - each corresponding to some big company switching their edge servers to HTTP/3 like Alphabet, Meta, Cloudflare. There is no gradual increase.
Furthermore, I don't see easy solutions yet for some problems with QUIC - for example browsers still try to establish a TCP connection first unless they know for sure the server supports QUIC. Proxy support for HTTP/3 is still in its infancy, but for many corporate envuronments it is a hard requirement.
So outside of the biggest websites, which I admit also take up a large chunk of the network traffic, is QUIC really replacing TCP in the general Internet?
> for example browsers still try to establish a TCP connection first unless they know for sure the server supports QUIC
As you alluded to here, you can hint a networking implementation with QUIC supporting servers. This feels similar in practice to HSTS Preloading, most of the benefit of full HSTS comes from a small number O(100k? 1m?) of domains being pre-loaded as HSTS supporting, and that's just distributed with browsers now, a fairly straightforward solution. The same could probably be applied for QUIC.
> which I admit also take up a large chunk of the network traffic, is QUIC really replacing TCP in the general Internet?
I guess this depends on whether you're looking at aggregated traffic, or distinct traffic destinations. Neither of those is more important right! If YouTube/Netflix move to QUIC, that's a very significant amount of benefit for the internet and users. Equally if all wordpress sites on shared hosting disappeared because TCP was no longer supported, that would also be a very significant impact. I think the headline saying "QUIC is displacing TCP for speed" is very fair, but over-extrapolating from this would be going too far.
Furthermore, I don't see easy solutions yet for some problems with QUIC - for example browsers still try to establish a TCP connection first unless they know for sure the server supports QUIC. Proxy support for HTTP/3 is still in its infancy, but for many corporate envuronments it is a hard requirement.
So outside of the biggest websites, which I admit also take up a large chunk of the network traffic, is QUIC really replacing TCP in the general Internet?