Can better hiring method avoid the need to fire staff? Could you create a culture that retains the right people and forces wrong people to leave?
No. It assumes that the "wrong" people now were the "wrong" people from the start. Your business changes. People change. The combination of those two factors mean that sometimes you have no choice but to fire somebody.
Your point about businesses changing reminds me of the arguments I've read in the past that there's too much full time employment and not enough freelancing. The idea is to get the best person for the task then move on instead of constantly trying to adapt everyone to the latest departmental needs.
No. It assumes that the "wrong" people now were the "wrong" people from the start. Your business changes. People change. The combination of those two factors mean that sometimes you have no choice but to fire somebody.