How will the junior estimate the complexity of something he does not understand? Either too short or too long. So the difference is not that big between points

How will the junior estimate the complexity of something he does not understand? Either too short or too long. So the difference is not that big between points and time. Also, in all the teams I’ve been the devs had no problem using the points. The managers are the ones that force a link between points and days. In that case the author says: just use the days.