Getting rid of that incentive would be a reason to call in sick more often.
This is such an American thing to say. The question wouldn't even occur to most European folk.
You do get guaranteed holidays, but sick days explicitly do not count as holidays. If you quit, you get paid for unused holidays.
For reference, I can only be legally fired if I'm sick for more than 186 days in a 365 day period.
Although some jobs (especially those with a pension) that have a sick day allotment will give you a credit for unused sick days. Eg my dad retired one month early because he had unused vacation and sick days.
Some jobs also give you a lump of time off and say "this is paid time off, you can use it for sick time OR vacation". But that's only for short sicknesses, like if you need 1-2 days for a cold. If you're sick for more than 5 days you get paid by the government instead of your employer
In Australia your sick leave accumulates but you don’t get paid out when you leave, while your accumulated annual leave does get paid out.