Pandemic policies must be evaluated on all costs and benefits, not only Covid-19

I don't know if there being no benefit is the consensus in other places, but it's not the consensus where I live. Yes, the risk to healthy kids themselves is small though non-zero, but kids a) do get the disease and b) are roughly as infectious as adults, especially particularly older kids.

Still, many leaders have embraced Zero-COVID-19 policies going forward, advising against resumption of normal activities even after widespread immunity.

Really? Which leaders? Haven't almost all countries affected by Covid reopened most of the way before the number of new infections reached zero? I don't think zero covid had any impact beyond being a talking piece. And how does widespread immunity figure in? Zero covid (and "no covid", another different but related proposal which they conflate) came up in Dec 2020/Jan 2021, when no place on Earth had anything like widespread immunity even in sight.

Some economists initially believed that shelter-in-place orders would save lives and benefit the economy.

I doubt very many economists believed that NPIs in and of themselves benefit the economy. But the damage to the economy from a pandemic that rages uncontrolled is also massive. That said they refer specifically to shelter in place mandates, which is an extreme measures that we here mostly avoided apart from a few weeks of nightly curfew out of months of NPIs.