By asking about kerosene "wearing out" do you mean wearing out like erosion & becoming thinner - which only happens to solid items not liquids.

Or, are you asking about will kerosene be fully depleted before oil is fully depleted - fully depleted meaning, no longer existing?

If you mean the latter, kerosene is not separate from oil. Kerosene is made from crude oil. Oil refineries take crude oil & separate out the separate fractions of crude oil kerosene, petrol/gasoline, diesel fuel, heating oil and asphalt are all created by oil refiners from crude oil.

When there is no more crude oil, or no oil refineries, there will be no more kerosene.

Generally, it might take the form:

C$_{16}$H$_{34}$ $\ce{->}$ 2 C$_8$H$_{18}$ (Octane, a typical petrol component)

Note that this is not balanced; to crack to fully-saturated products we need to add hydrogen, usually made from natural gas and water. This is why you sometimes see that a refinery will take 1 tonne of heavy crude and make 1.1 tonnes of petroleum products. This is called 'refinery gain'.

Essentially, as long as we have hydrocarbon feedstocks, we can make kerosene.