Is it true that the succession of Abu Bakr Al-Siddiq was not by consensus, due to the non-participation of Ali and his companions in it?

Neither Ali (may Allah be pleased with him) nor any other companion denied Abu Bakr's priority to the Caliphate. He pledged allegiance to him twice: The first was on the day of Saqifah, where Umar, the Muhajireen, and the Ansar all pledged allegiance to him. Then, Zubair and Ali pledged allegiance after Abu Bakr called upon them. The second pledge of allegiance occurred after the passing of Fatimah (may Allah be pleased with her), when Ali sought reconciliation with Abu Bakr and pledged allegiance to him, after having observed the people's disapproval. Ibn Kathir emphasized that the second pledge of allegiance confirmed the first, and that Ali was not estranged from Abu Bakr during the six months between the two pledges. Rather, he prayed behind him and attended his gatherings for consultation. The Companions unanimously agreed on the superiority of Al-Siddiq and his rightful claim to the Caliphate.