> the "http" scheme associates authority with the ability to receive TCP connections on the indicated port of whatever host is identified within the authority component. Because HTTP/3 does not use TCP, HTTP/3 cannot be used for direct access to the authoritative server for a resource identified by an "http" URI
Was the possibility of using a different scheme (maybe http3 or h3) considered in addition to the altsvc mechansims?
TL;DR just like HTTP/2, we wanted to avoid friction in deploying these protocols. Having to rewrite URLs because of new schemes is pretty unpalatable, it has major impact. Instead, HTTP/3 can rely on other IETF-defined mechanisms like Alt-Svc (RFC 7838) and the more recent SVCB / HTTPS RR [1] DNS-based methods. The latter has been deployed on Cloudflare a while [2] and supported in Firefox. Other user agents have also expressed interest or intent to support it.
The net outcome is that developers can by and large focus on HTTP semantics, and let something a little further down the stack worry more about versions. Sometime devs will need to peek into that area, but not the majority.
Was the possibility of using a different scheme (maybe http3 or h3) considered in addition to the altsvc mechansims?