I´m currently looking to implement an intraday volatility model and I´m new at the quant world and I learned how superior is GARCH family is for daily volatilities, but in the research stage I found out that GARCH daily model is not good for intraday volatilities. Instead, they present a realized GARCH or use realized volatilities models, so I was wondering if someone can give a simple explanation of why is that?
I would be really thankful for your answer.