Most poor families can afford medical insurance, either through state Medicaid programs or using subsidies available on state exchanges. Overall the USA is at or near the top of countries in terms of 5-year cancer survival rates. We're actually doing better than countries with socialized healthcare systems, although there are problems with access and cost that should be fixed.

As an asset class, healthcare companies don't consistently have a higher ROI than any other sector. Regular people should generally diversify their investments with broad index funds rather than making concentrated bets in a single sector.