Please give an example of a nation which was highly successful in isolating old/at-risk people during COVID, while letting the epidemic run wild.

Florida

This was entirely the correct decision given that old people are often at substantial risk from Covid, and children almost none. "Old people are retired and can stay at home" betrays huge ignorance of differing socioeconomic conditions as well as social needs of the elderly.

But old people can self isolate. How are they at risk if they stay at home? Children might not be affected that much, but still spread it, and apparently much harder to keep inside 24/7. Playgrounds were as crowded as always. My neighbor told me that her daughter was one of five children from the entire class staying at home, for the remaining 20 kids, their parents got a written confirmation from their employers stating they're essential, and thus their children were eligible for "emergency care". Ridiculous.

I'm not entirely sure things would have dragged along so much had we just eliminated children as spreaders first.

Can they self isolate? Do old people not need to go to the grocery store, doctor's offices, the hardware store to get parts for their broken toilet, etc?