Rafa’ul Yadain is the act of raising your hands up to the ears before the first takbeer, everyone does it.
But it is after the first takbeer that matters get fuzzy. You see Rafa’ul yadain does not only happen in the beginning, according to a hadith of Bukhari, the prophet (saw) raised his hand once in the first takbeer, then before going into Ruku and then after standing up from ruku, he did this in all the Raka’aats.
You might then think that how could there be an issue of dispute here, isn’t that sunnah?
This is exactly why it is an issue of dispute, because it’s a sunnah, the people from Hanafi school of thought are mainly the ones to differ. They give many references of the Sahabah (which are completely valid) like that of Abdullah ibn Mas’ood who during the time after the passing of Prophet (saw) said to the jama’at “shall I not pray the prayer of prophet (saw) in your presence?” he then moved on to pray and raised his hands only once in the start and that was all.
A similar instance occurred at the time of Ali (ra) when he was the khalifah he used to lead the prayer and did not raise his hands except for in the beginning. This confirms the fact the it is a non mandatory sunnah, if you follow it you get the reward for following sunnah, and if you don’t there is no problem at all.
But it is the people who make it seem like a problem, I myself have experienced a lot of judging eyes for doing or not doing the Raf’ul yadain, people go without looking at the whole picture and make big issues out of little things.
Fun fact, did you know that even keeping your hands up and folded on your stomach part is sunnah? You can keep it down and just stand and it would be totally fine, people who follow the Maliki school of thought do this often.
The more you know.