however, at the same time this treaty allowed ummayyyads to consolidate their rule over a period of 20 years.
It is sad that non-Shias could only think in terms of rulers and monarchies. The Imams showed that leadership (imamat) is more than just subjugating the bodies. Imam Ali was bathing Prophet's body when people were fighting for khilafat in Saqifa. Imam Hasan made treaty with the killer of Sahabas to stop bloodshed. Imam Hussein never demanded to be the khalifa himself. Same goes for all other Imams of Prophet's family.
However, Muslims knew very well who are the people worthy of khilafat and leadership.
So as soon as Abbasids rose up against Muawiya's family, calling upon Muslims to return the khilafat to Banu Hashim, masses upon masses of Muslims supported their call.