A dripping tap is not just waste. It is a worn component telling you it has reached the end of its life.
Traditional taps seal with a washer pressing onto a seat. When the washer wears, the tap drips. Left long enough, the seat itself scores, and then a new washer will not seal either, which turns a minor repair into a tap replacement or a seat reseating.
Mixer taps work differently, using a cartridge rather than a washer. When a mixer drips or becomes stiff, the cartridge is usually the part at fault, and cartridges are specific to the model rather than universal.
Water hammer is a related complaint worth mentioning: a bang in the pipes when a tap or appliance shuts off quickly. It is caused by moving water stopping abruptly, and over time the shock can loosen joints, so it is worth addressing rather than tolerating.
If a hot water system is leaking, making unusual noises, or delivering water hot enough to scald, switch it off at the isolation point if you can do so safely and call a licensed plumber. Tempering valves and pressure relief valves are not do it yourself items, and a failed relief valve can be dangerous.