I gotta push back on some of this. COVID 19 is killing overwhelmingly the elderly with comorbidities. While it's true we have no immunity (I assume you mean, "antibodies"), none is needed for the younger demographics to recover. It's different than influenza in that regard which kills many from all demographics, but especially those with no antibodies (consider the 1918 flu).
We also know that herd immunity builds completely on its own as people become infected and recover and the virus has no new hosts to infect. The question we're asking in this case is, "How fast can we allow this to spread in order to have tolerable losses amongst (mostly) the elderly assuming our minimal preparedness and excess capacity." "Tolerable" is a moral judgment. The bean counters are never going to allow a lot of extra unused beds, ventilators, and excess capacity in case of a pandemic which is why you've repeatedly said, "We were already running at 90% capacity." They've traded-off profits over lives. Because of their tradeoff, we're being asked to tradeoff jobs and the economy for lives. This is a temporary fix. As Dr. Ioannidis said, job losses, isolation, and economic ruin lead to plenty of deaths also. I can tell you that the R value of unemployment is very high right now and we're not going to tolerate lockdown much longer. We're being eased back into an alternative sooner rather than later IMO.