In the fifth paragraph you mentioned that the equity market risk premium "has basically disappeared" but I think you might have made a mistake because the axis goes from 4.5 to 7.5% so the fact that is at the bottom of the graph does not mean that it has disappeared just that it has eroded a little bit.
You also say that the market risk premium is "the famous beta of the CAPM model" but the market risk premium is not the beta of the CAPM. Beta is a measure of the correlation of the volatility of an individual stock or a portfolio to the volatility of the market and then in the CAPM we use both the beta and the equity market risk premium to estimate the expected return of an individual stock or a portfolio.
In the fifth paragraph you mentioned that the equity market risk premium "has basically disappeared" but I think you might have made a mistake because the axis goes from 4.5 to 7.5% so the fact that is at the bottom of the graph does not mean that it has disappeared just that it has eroded a little bit.
You also say that the market risk premium is "the famous beta of the CAPM model" but the market risk premium is not the beta of the CAPM. Beta is a measure of the correlation of the volatility of an individual stock or a portfolio to the volatility of the market and then in the CAPM we use both the beta and the equity market risk premium to estimate the expected return of an individual stock or a portfolio.