Because it is unfair. It just tends to benefit people employed today

It's not about being fair to the individual, it's about producing a better outcome for society. In this case, saving money on welfare (that's also in great measured pooled across society, not an individual account).

Parents being able to take sick days to care for their kids, or 50yo being able to take leaves to take care of their dying 80yo parents are also unfair to kids in their 20s just starting out.

The only fair system is a random lottery - which is also the most terrifying for everyone.

Then again, if we did have a random lottery that required all employees (up to and including the CEO) to participate, then perhaps we'd see fewer layoffs...

why would the company want that?