Type 83 grows because it combines specialized fleets

Why would Type 83 grow from roughly 8,000 to 14,000 tons or more when technology often gets smaller?

Because it must carry many more missiles, power and energy storage, long-range fuel, command spaces, and several specialist missions in one hull.

Missile depth, electrical generation, energy storage, range, speed, crew accommodation, and command capacity all add weight even when individual electronics become smaller. A larger vertical-launch battery adds weapons and the structure needed to support them. Lasers or electromagnetic weapons would demand heavy generation and energy-storage systems, while worldwide presence requires fuel and habitability. The proposed ship is also expected to combine Type 45 air defense, Type 26 anti-submarine work, land and anti-ship attack, and Type 31 presence. Combining several specialist ships' missions in one hull makes Type 83 functionally a large cruiser even if officially called a destroyer.