But you're only "supposed" to use POST with requests that add/modify data, or something silly like that.

In practice, QUERY is most useful for where you want a bunch of different verbs for the same endpoint and need a body.

QUERY is cacheable.

... in theory only. Not that many http cache programs support QUERY. And many HTTP middle-boxes bans non GET/POST verbs.

For now. Change has to come from somewhere.

And retry-able.

I do... but there are good reasons to not want to. If you read the linked spec you can learn for yourself

https://httpwg.org/http-extensions/draft-ietf-httpbis-safe-m...

In practice I think that’s exactly what many people do.

GraphQL is doomed?

No, this would actually be very useful for GraphQL API's.