If the price of bitcoin is below the mining price, the first time it will get a bad impact is bitcoin miners, then the traders and temporary bitcoin holders. they will feel panic and might stop their activities.
At the same time they might seek for something for them to have a replacement to mining that will cost less and they can earn more. If people tends to love what they are dong, they will probably seek for ways. Therefore if it happens some may leave crypto but those who believes in bitcoin will probably find there way.
It will give big impact for miners if bitcoin price below mining cost. Miners will move to mine others profitable coin because peoples who involve in crypto must be looking for profits. Maybe bitcoin transaction will more slower than before price drop