Drippy kitchen faucet

[LunaSea]

4. You need not replace the entire assembly

Just the rubber/plastic disc at the bottom of the 'cartridge'. It's called the seat and usually gets gummed up with tiny bits of debris from your water supply. Sometimes you can get by with simply cleaning it, or in some cases flipping it over. It's the part responsible for stopping the water flow. Sometimes they'll get deformed from repeated tightening and lose the shape required to make a seal. It's not too difficult a repair if you have an adjustable wrench and a screwdriver. Turn the water supply off first or you will be very sorry.

Like many foreign manufactured home products, the quality of materials has been in decline for some time now. Steel and brass have been replaced by more brittle forms of zinc and other cheap metals. Having parts suppliers fold up and disappear on a regular basis means yes,
sometimes you end up replacing the entire assembly.