[theowaway213456]

Obviously the approach you mentioned has the downside of two server round-trips being necessary while the QUERY request only requires a single round-trip. Not to mention the two-request approach adds more complexity to both clients and servers, as it mandates that both the client and server have to physically create and manage those resources.

[nesarkvechnep]

Obviously, yes, but is it simpler to add a new HTTP method and add support for it everywhere?

[lightningspirit]

Because HTTP is stateless by definition, you now need to support persistence (state) on the server side whenever you want to run a slightly different query, which contradicts the preamble.

I understand the confusion around GraphQL's cached/persisted queries, but this is not the intention of HTTP.