Earlier quoted context omitted.
A pool of sickdays? What the? Is there a pool of cancer days too?
I share your shock, and try to keep myself from feeling that the current situation in the US is either normal or ethical. To answer your question, yes, recovery from cancer would could from the pool of sick days in most places in the US. If the recovery takes more than the pool of sick days (7-9 days per year, somehow and perversely being different on average by seniority[0]), then all remaining recovery time is unpa…
It's not nearly as barbaric as you're making it sound if you actually understand how it's supposed to used.