How would we have had another 3-4 million dead? All any restriction did was delay exposure. Yes, a vaccine arrived but one which has questionable efficacy and which wanes in effectiveness (hence the booster programme). All we did was spread out any Covid related deaths at huge costs.
I don't know if it would have been that high, but the whole (initial) idea of "flatten the curve" was exactly that. Saturated systems stop working as expected. When hospitals reach capacity then neither covid nor non-covid patients will get adequate treatment.
"Questionable efficacy" in what sense? You can argue that possibly for transmission, but certainly not for endpoints like death. See the recent Lancet study, for example.
