Bitcoin mining is a good concept which provides reward for miners who help to solve the transactions.But,nowadays,has it made bitcoin get accumulated in the hands of only those who can afford thousands of dollars of ASIC hardware? Has bitcoin been centralized?
No, bitcoin mining is not centralization, although there are people who buy thousands of dollars asic miners
because right now will be difficult for 51% attack on bitcoin network by one person,
they buy asic miners for investments in hardware miners and mine bitcoin of course with calculate return of investments.