Here's another opinion, unfortunately more than ten years old now, from a voice I trust more than Shivani's: A.E. Stallings.
https://www.poetryfoundation.org/har.../11/no-contest
One additional point: When is one supposed to learn the rule that only
first books may be published via contests? I seem to have committed some faux pas
as have recent winners of the New Criterion Book Prize John Foy and Moira Egan, both of whom had books out before their contest wins.
My first book was from WordTech, not a contest, and I'll talk about that in private if you want to talk.