If a house takes 9 months to sell, it is way overpriced for the market.
Maybe, maybe not. If it sold at the higher price, it was worth it to some people.
Maybe the seller is in no particular rush to relocate and their main goal is to maximize price.
Other people need speed because they have to relocate for a new job etc.
A retired geezer maybe has time to spare and is less interested in speed that maximizing price.