WaPo:
This is, in large part, a crisis of the Kremlin’s making. If Peskov can’t make Putin reappear, the obvious thing to do would be to furnish some plausible explanation, like, “The President has come down with a bad case of the flu but is following all developments and will be back at work shortly.”

But that statement is impossible for two reasons. First, manly men don’t get sick. Putin’s carefully cultivated image rests on never showing weakness, which is crucial in hypercompetitive Russia. If one shows some weakness, then one is all weakness—and therefore prey. This is why Putin never apologizes and, in the rare instance in which he reverses a decision, will do so long after the public gaze or outcry has moved on. Putin is the national leader and does not admit mistakes. It is beneath national leaders to do such lily-livered things.