There could be honest but non-obvious reasons. Maybe they need multiple renovations before they can get a certificate of occupancy but the local permitting office is Kafkaesque, or the site needs environmental remediation before it could be rented but the owner doesn't want to deal with it so they're trying to find a buyer instead of a tenant, or they have to finish suing the previous tenant who messed up the unit before they have the money to fix it, or the landlord took out an adjustable-rate mortgage right before interest rates went up and WFH started and is now bleeding cash and waiting to see if rates come back down to decide whether they want to invest new money in finding tenants or just file for bankruptcy.
One of the serious possibilities is that they're dumb. Lots of idiots exist, some of them buy real estate. They're asking for more because they erroneously think they can get it and then they're wrong so the unit is empty. They eventually either figure this out and lower the price or they run out of money to pay the mortgage and the bank comes for them, but either of those could take an arbitrarily long period of time.
One of the serious possibilities is that they're dumb. Lots of idiots exist, some of them buy real estate. They're asking for more because they erroneously think they can get it and then they're wrong so the unit is empty. They eventually either figure this out and lower the price or they run out of money to pay the mortgage and the bank comes for them, but either of those could take an arbitrarily long period of time.