Spear is finesse. You don't need to swap unless you're looking to use a bow for ranged purposes. So, in certain situations spear-builds outpace pure strength melee builds.
Furthermore, you can still use warfare skills with a spear and do a ton of damage despite being primarily Finesse. Also, reach, and bonus from 2H. It's basically the same as a knight except you lose some of the top damage for the ability to do competitive ranged damage.
