That is an oversimplification and inaccurate considering the comparable productivity experienced throughout much of the corporate world throughout the pandemic. I suspect this might have been the sentiment among some, but if you were working from home, you were working nonetheless. One of the challenges has been people not setting boundaries and working longer hours because the lines between work and home were blurred early on.
As for poorer people bringing things to white collar workers, the pandemic didn't change that dynamic since deliveries were always part of that workflow. The increase in deliveries and quotas on how many people could go into shops helped make it a bit safer for workers as well. That demand for deliveries also helped keep businesses afloat who in turn kept people on the payroll.
That COVID 19 impacts the elderly and those with co-morbidities was never a question or a point no one understood or understands. What differs is how risk is calculated, and thus far you have focused narrowly without including the factors which make it risky for those particular groups. One simple can't isolate those at risk because if we start with obesity as a criterion, you're talking about 1 in 3 people in the US and 1 in 4 people in the UK having to isolate. The disease depends on people carrying it, so while the young may not die, they're spreading it to those at risk. Sure, it would be easy to just grab all the vulnerable and place them on Quarantine Island to keep them safe, but that just isn't realistic.
I don't know of any children dying, but a co-worker lost his 39 year old sister recently. The people who I knew who passed were in their late 50s, not overweight but had heart issues. Not knowing anyone who has died from a disease is a pretty poor metric in determining gravity or prevalence. I never knew anyone who died of AIDS or Ebola, but they're deadly diseases I'd feel better about if I knew health agencies were doing everything in their power from them spreading.