This allows you to wash in one load what used to require two. It also means you can wash as many as four large items like sheets at one time. Because you won't always have full loads, agitators have water level settings ranging from a few items to not quite a full load. If you live in an apartment or don't want a large capacity washer, there are compact models that wash smaller loads and fit into limited space. Soaking is not passe.
Many wash loads benefit from it.
Some washers have an automatic soak cycle that agitates the clothes for a few minutes, soaks without agitation and then spins out the water. Some models proceed automatically to the regular wash cycle. Others must be reset. Many homemakers have the mistaken idea that the longer the wash time, the cleaner the clothes. Any washer you buy will have sufficient time on the dial for anything you will launder.