Why a fusion warship would begin as a very large vessel

What would a fusion-powered warship look like?

Probably a very large, power-hungry ship able to justify an expensive plant and specialist crew, and unlikely to appear even experimentally for more than fifty years.

An early fusion warship would be large because the plant would be expensive, power-intensive, and dependent on exceptionally skilled personnel. A small combatant would struggle to justify that infrastructure, so only a vessel with very high electrical demand could make the installation worthwhile. The panel also cautions that even an experimental design is probably more than fifty years away.