Yes, we should have saturated hospitals even more, it would have had no effect on mortality!

https://youtu.be/0P8KyaYuaTg?si=emkhsme03r9shDxE

Italian and New York hospitals were overwhelmed because a) both places put sick elderly into old age homes. (42% of US COVID19 deaths in 2020 occurred in old age homes!) b) Like elsewhere early on, doctors put everyone serious onto ventilators in a mistaken belief that they should treat patients like they do ARDS cases based on blood oxygen levels. This damaged healthy lung sacs and caused long-term dependence on mechanical respiration that doctors found almost impossible to wean patients from, and other side effects like deep vein thrombosis; Nick Cordero is an example. (This article from April 2020 <https://www.statnews.com/2020/04/08/doctors-say-ventilators-...> was completely vindicated in retrospect.) Neither happened after the first few months.

And no, none of those field hospitals built in parking lots and stadiums everywhere were used, either. In Wales, for example, Millennium Stadium was converted into a temporary field hospital with 300 beds and capacity to expand to 2000 beds. It was such a big deal that a public contest was held to name it Dragon's Heart Hospital <https://en.wikipedia.org/wiki/Dragon%27s_Heart_Hospital>. However, said hospital never had more than 46 patients at one time, and was closed in six weeks for lack of use!

Even in NYC, which really did see overloaded hospitals briefly in March-April 2020, USNS Comfort treated a total of 179 patients. USNS Mercy treated a total of 77 patients in LA.

You left out (c) cases were rising exponentially, so even if doctors could have handled X number of patients, they would become overwhelmed a few days later when that turned into 2X. Virtually no one in the population had immunity to SARS-CoV-2, so the only way to stop the exponential rise was a dramatic reduction in face-to-face contact between people. That could occur through spontaneous change in public behavior (e.g., everyone avoiding public places as much as possible, or everyone wearing then-unavailable N95 masks in public), from public policy ("lockdowns"), or from both. But continuing on as normal would have led to hospitals being overwhelmed, no matter how efficiently they were run and how skillfully they treated the patients.

To your point (a), old-age homes should have been much better protected, but it's virtually impossible to shield them off when the virus is raging outside. The most effective way to protect the elderly would be to reduce transmission of the virus in society as a whole.

To your point (b), that's what happens in a pandemic. There's a completely new disease, and doctors don't know how to treat it effectively. Everyone is trying to do what they can, based on experience with treating other diseases. You can't base public health policy around a belief that doctors will instantly know the correct way of treating a pandemic disease. You have to take dramatic measures to reduce transmission in a situation like New York faced in early 2020.

This is a garbage-in, garbage-out analysis, akin to saying, "We analyzed 100 cities, and found that those with levies were more prone to flooding. Thus, we conclude that levies offer no protection against flooding." We know mechanistically why levies work: they block water. We know mechanistically why lockdowns work: they reduce transmission. Less transmission means fewer infections means fewer deaths.

You can see this most clearly in the zero-CoVID countries, which had dramatically lower death rates during the pandemic. Taiwan and China had virtually zero deaths for much of the pandemic, because they traced literally every infection chain and capped it off. They reopened after vaccinating most of their populations, which means that most people in those countries had a primed immune system when they first got infected. As we know from numerous studies, that dramatically reduces mortality.