> For a small test page of 15KB, HTTP/3 takes an average of 443ms to load<p>443 milliseconds!! When typical user latency is sub 50 milliseconds, requiring 443 milliseconds to get a lightweight page displayed on the screen is terrible.<p>Users perceive 100 milliseconds as near-instant, and that ought to be the target. With 50 milliseconds of network latency, and 0-rtt support, that gives 50 milliseconds for server and client processing+rendering. Ought to be very do-able.<p>The fact it has not been done really is a failure of software engineering as an industry - we always favour more layers of abstraction over perfecting the user experience.
Now compare the performance of HTTP/3 versus HTTP/1.1 over multiple years when the website isn't run by a corporation paying an engineer to babysit and maintain it. The HTTP/3 CA TLS HTTPS-only setup would start failing due to CA TLS problems eventually (in a year or two) while the HTTP/1.1 HTTP+HTTPS would remain accessible forever. This is the core problem with HTTP/3 for human people.<p>It is one that could be fixed by developers if only the correct flags were set during compilation of the HTTP/3 libs and during their linking to the relevant browsers. But no one seems to care about human use cases. It's corporate security uber alles.