The answer to 'why is my faucet overflowing' is that there is likely a blockage or issue with the faucet's internal components. This can cause water to back up and overflow the sink. Common causes include a clogged aerator, a broken washer, or a problem with the faucet's cartridge or valve.
Symptoms of an overflowing faucet can include water spilling out of the sink, a steady stream of water coming from the faucet even when it's turned off, or water pooling around the base of the faucet. To fix the issue, you'll need to disassemble the faucet and inspect the internal parts for any clogs or damage.