Work Smart, Work Better
If you ever tried taping drywalls together by freehand, you'll know exactly hard it is. You'll first have to apply the mud, even it out so that the tape can be applied, apply the tape, then clean it once more to get rid of the excess mud. Since you're doing everything separately by hand, there might be some irregularities which can cause the tape to rip or be applied unevenly. If you are looking at a large project, it might be just worthwhile to purchase a taping tool to make the process much easier and faster.