Some good points, although I'd toss another thought into the mix. The confinements and shutdowns and shelter in place orders also cost lives. We know that recessions cost lives. One study (published in The Lancet, so worth taking a second look at) suggested 500k excess cancer deaths from the global financial crisis[1], and another study (published in the BMJ) suggested that excess suicides in 2009 alone across the US…
If the movement restrictions cost lives, why are total fatalities down? (even including SARS deaths)
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.