Not in isolation, no.

E.g. FIRE. It's not unfair that those who retire early don't continue to get a salary.

It's not even unfair (on its own) that those who are irresponsible with credit cards to go on trips, instead of investing in their future (e.g. staying home and learning), later have lower income.

That's not unfair.

What does 'unfair' mean in that dictionary system?

Why does a vest have no sleeves?

Depends on the dictionary you're re using and where you look, in a Dutch dictionary a 'vest' can be a knitted button-down sleeved sweater ('een kort gebreid jasje met mouwen').