Pre-existing conditions are not omitted from the 0.5%/month mortality rate. They just aren’t as impactful because most 80 year olds don’t have immediately life threatening medical conditions. For every 80 year old who will die this month from cancer (or Bubonic plague, sure, why not) there are 199 others who won’t. But if those 200 people all have COVID-19, it will kill another 30 of them. Attributing 30 vs. 31 deaths to COVID-19 just doesn’t matter that much.
80 year olds have better coverage than younger Americans on average because of Medicare, despite Medicare’s generally lower reimbursement rates compared to private insurance, simply because so many younger Americans don’t have insurance at all. And I think you’re dramatically overestimating the strength of the incentives at play if you think medical professionals are defrauding the federal government en masse to line their employers’ pockets.
You probably don't want to rely on that last statement. Having worked in the hospital sector, they in fact do and are proud of the fact (I've literally sat in presentations about the software and automation employed to do so as well as all hands meetings touting this as competitive advantage) that they upcode as much as possible without risking jail time to maximize revenue. The existence of all those specialty centers around hospital networks are specifically to support this model as well.
80 year olds have better coverage than younger Americans on average because of Medicare, despite Medicare’s generally lower reimbursement rates compared to private insurance, simply because so many younger Americans don’t have insurance at all. And I think you’re dramatically overestimating the strength of the incentives at play if you think medical professionals are defrauding the federal government en masse to line their employers’ pockets.