I don't think that even the most dire models/predictions said that millions would die without a lockdown. Certainly not in Canada.
I have looked for models worldwide ... one predicted 40 million dead with no lockdown and this would seem to be one of the most pessimistic:
Without any interventions like social distancing, one model predicts the coronavirus could have killed 40 million people this year
So let us assume that's true. My argument is that millions WILL eventually die prematurely due to the lockdown. We already have the UN predicting 30 million dying due to starvation because of the breakdown of supply chain and failure to plan in countries like India where they even locked down their farmers. That's already 3/4 of the "no intervention model" of deaths, then we must factor in the reduced standard of living due to a destroyed economy, depression, suicide, drug abuse due to job loss and the negative effects of being locked up with no way of knowing if the government will ever let people out again. And that's the short-term stuff. I think this easily adds up to a lot more than 40 million within the next few years.
Then we must consider long-term. They are predicting 35% unemployment in the US after this. Canada will be similar. It will take decades to recover from that. We are condemning our children and grandchildren to a much lower standard of living than we have enjoyed because of the economic destruction.
The counter argument is that the economy would have collapsed worse without the interventions, but I don't see how you get worse than the government overnight unemploying 60% of the population. That would not have happened even in a worst-case model.
We are essentially trading short term "gain" (i.e. fewer deaths now) for longterm "pain" in my view. Kind of like how we rack up government debt. We kick the can down the road for our children and grandchildren to suffer the consequences.
Yes, I strongly disagree that this is a cataclysm. A cataclysm would be sometime like a World War or deaths that compare to that. I think we've had it so good for so long that we've lost a bit of perspective on what an actual catastrophe looks like.