where are we going?
There's a lot of other reasons for practicing a lot of cuts with a bokken. For someone who is weak, developing some strength might be one of the first benefits. For someone who already has sufficient strength — form, accuracy, and ki development are some other benefits.
Once again, aikido is not about using strength or strength development. It's about using certain movements such as a sword-strike motion, with aiki in unarmed waza such as shihonage.
If the goal is not kept in mind, it will never be reached.