Why did king louis xvi convert the estate general?

When Louis XVI gained power in 1774, France was heavily in debt due to many of their previous wars in Europe. Louis XVI at first supported radical financial reforms that increased taxes on the nobles. The nobles of course, didn't like it and they continually insisted that the King didn't have the power to levy new taxes. The king then changed his mind and sided with the nobles, dismissing the proponents of those reforms. In 1776, Jacques Necker replaced one of these proponents. Necker wanted support for the American Revolution and proceeded with a policy of taking out large international loans instead of raising taxes. When this policy failed miserably, Louis dismissed him, and replaced him in 1783 with Charles Alexandre de Calonne, who increased public spending to 'buy' the country's way out of debt. Again this failed, so Louis convoked the embly of Notables in 1787 to discuss a revolutionary new fiscal reform proposed by Calonne. When the nobles were told the extent of the debt, they were shocked into rejecting the plan. This negative turn of events signaled to Louis that he had lost the ability to rule as an absolute monarch. As power drifted from him, there were increasingly loud calls for him to convoke the Estates-General, and in May 1789 he did so, summoning it for the first time since 1614 in a last-ditch attempt to get new monetary reforms approved. The Estates-General was an embly of representatives from almost all sectors of French society. The Estates-General didn't meet for so long because most of its members (97%) belonged to the the Third Estate which was composed of commoners. The First and Second Estate (clergy and nobles) only made up a combined 3% of the Estates-General. Thus, the higher-ups in French society at that time feared that conveying the Estates-General would result in empowering the commoners. But the dire economic conditions during Louis XVI's reign, the failure of officials to lift up the economy, and the belief that Louis XVI was losing power as a monarch was enough to convince him to convene the Estates-General.