Which of the following is an important problem with our reliance on betas and CAPM for capital budgeting purposes?

Neither beta nor CAPM appear to capture any information related to actual stock or market returns we have observed.

Both aim to help us understand the future. And yet, the inputs to both are usually based on historical data.

Both aim to help us understand something about risk. And yet, there is no economic explanation for why beta measures anything related to risk.