In 1997, Apple was on the verge of bankruptcy [1]. That experience deeply scarred the company's culture. Prior to that, Apple didn't hoard cash (relative to revenues). Afterwards, it did.
At this point, the instinct is overplayed. But cultures are difficult to change. So the obsession with runway remains.
[1] https://www.businessinsider.com/apple-comeback-story-2010-10...