This may be stating obvious, but the price is what a buyer will pay and a seller will sell. You need both. And a seller and a buyer can both be irrational in setting their bid or ask.
I sold a house last year, and got a good bit above asking. But you wouldn't believe the number of low-ballers after a month on the market telling my EA what the value of the house was and what their rationale was for the offer below asking. "I could renovate the house up the street for 50k, so this is worth X not Y". And a tip - unless you have actually renovated a house before, you are underestimating the cost.
Unless the seller is motivated (i.e. must move - found a dream house, executor sale, new job down the country, divorce), then many just wont sell unless they get the price they want or need. the optional sales like downsizers or potential trader uppers, may not really be compelled/motivated to do anything.