For a given wattage, voltage and current can be adjusted (inversely proportional) within reason, but higher current with lower voltage results in some problems:

For a given wattage, voltage and current can be adjusted (inversely proportional) within reason, but higher current with lower voltage results in some problems: voltage drop (which mostly only matters at long distances, typically negligible within an office) and thicker conductors (double the cross-sectional area for double the current, if memory serves). This is why things like PoE and phantom power for audio are often 48V instead of something lower.