Authors often view query writing as something that will end once they sign with an agent. I’m sorry to tell you that the art of writing a blurb (and query) will never go away. In fact, it will only become more common as you edit and write and help write cover copy, catalog copy and other things required by your publisher. In other words, get used to writing queries.
I was asked recently if agents ever use the query to pitch an author’s book. All the time. In fact, my best pitches to editors were those I lifted straight from the author’s original query. It is also those pitches that came on to become (with tweaks of course) catalog copy, cover copy, and the sales pitch.
The art of the query is not something to blow off. It is something to work to perfect, just like the art of writing a novel.