If you look at the remaining constitutional monarchies in the world ie Sweden, Japan, Jordan, Norway, Denmark, Spain, Luxembourg, the UK, Australia, Canada, New Zealand and the Netherlands and Thailand they are almost all wealthier, more prosperous and more free than the average republic. There are only a handful of absolute monarchies left in the Middle East but even they are richer per head than most of the rest of the Middle East.
India has been independent for over 70 years, it still has billionaires sitting alongside those in effectively absolute poverty. It cannot keep blaming the British Empire
You don't know who could become President in a republic, that is the whole point, as the US for example found with President Trump. Constitutional monarchy at least provides stability as head of state