Fittings (faucets and valves) are used more often than any other part of the plumbing system. They get plenty of use but are built to take it, under normal conditions.
The best modern fittings are all chrome-plated brass and will last a lifetime under everyday use. They clean easily with soap and warm water.
Caution: The metal chromium is easily dissolved in hydrochloric acid and sulfuric acid. Muriatic acid has for years been considered a good tile cleaner, but only where there are nickel-plated plumbing fittings. Where chrome plating is present, clean bathroom tile with warm oxalic acid, never with muriatic or sulfuric acids. Even covering the chromium surfaces with clothes will not prevent the acid fumes from inflicting permanent damage.
Gaining in popularity are polished brass fittings and trim. These will hold up well, as long as certain precautions are observed. Never use any abrasive cleaner on polished brass. This can scratch the protective coating on the brass finish resulting in deterioration or pitting of the brass plating. Also, avoid the use of solvent-based cleaners because they can harm the polished brass finish.
New technologies have brought about the development of improved finishes that withstand more wear. Check the manufacturer's warranty to determine whether or not you have the "new and improved" lifetime warranty finish.