Direct detection would be a lot more informative. It&#x27;s also hard.<p>There are a lot of systematic effects (foregrounds, etc.) that can matter to CMB measurements.<p>Any indirect glimpse is still quite valuable, as deviations from the standard plan might be apparent. Any measurement of the neutrino temperature at decoupling is interesting.<p>(Edit: I&#x27;d also note that the last great prediction of the Big Bang is &#x27;inflation&#x27;, something about which we know next to nothing.)