The primary risk factors of economic recessions take years. Most cancers take years to kill people. The effect of unemployment on suicide peaks at around 2.5 years of unemployment [0]. I think that we're going to have an economic downturn with repercussions that will last long after a SARS-CoV-2 vaccine exists. I also think the ends currently justify the means, but that's just a gut feeling I've got.
[0] Milner, Allison et al. “Long-term unemployment and suicide: a systematic review and meta-analysis.” PloS one vol. 8,1 (2013): e51333. doi:10.1371/journal.pone.0051333
1) You're looking at net lives, and there's no particular reason to think we're net negative yet. Let's imagine a brief lockdown to avoid overwhelming the emergency rooms with people needing ventilators is very net positive. And let's imagine crippling the economy by fully locking down everything until a vaccine passes clinical trials in 18 months is very net negative. Even if you accept these as true, we might have weeks to go until the crossover point arrives...or we might have already passed it.
2) Which brings us to the next point - even if we're already in net negative territory, deaths from Covid-19 are (hopefully) front loaded; they're happening now. Deaths three years from now because the long term economic growth rate is 0.2% lower than it otherwise would have been are still in the future. I linked to some studies suggesting the GFC cost a fair chunk of lives in the end, but you wouldn't have been able to detect any of that the week after Lehman failed; the fallout had yet to land.
And finally:
3) Coming back to the point in the linked article, there's more to life than strict maximising quality-adjusted life years. There's a lot of ways you could, in principle, save lives via a stroke of a pen. Boxing, white water rafting, surfing, diving, and mountain climbing are all shockingly dangerous sports. We could ban them! It'd straight up save lives. Should we? I, for one, would strongly argue no. But that cuts both ways. Even if we had inarguably correct data showing continuing the lockdowns was starting to cost lives, that's the starting point for the debate, not the conclusion. We don't (and shouldn't) just do the things that would save the most lives.
Regarding point 3, I think your examples, being individual sports that people choose to participate in, are kind of straw men. For one, relatively few people die doing them. For another, as I mentioned, they're activities that people participate in, knowing that there are some serious risks.
A better example would be "let's end all farm subsidies for sugar and tobacco." You could arguably include corn here, as well. Go a little further, and you can start talking about national sugar and tobacco taxes. All these measures simply increase the price of sugar and tobacco, which has been proven to reduce consumption, and would certainly have the effect of reducing obesity and cancer.
I find it a lot harder to argue against those things than to say we should ban surfing, boxing, or rafting, because a few people get injured or die every year doing them.
My point isn't that they're equivalent (they're not), but that the analysis never stops at "this will save lives, so we should do it". There's always more layers, such as here your very valid analysis of whether people are choosing to participate.
No, but you'd get the point across better by using a less ridiculous example -- that's my point. Nobody's ever going to support a ban on surfing because it's just ludicrous on its face. Ending tobacco and sugar subsidies is something that could get real consideration today.