It should be noted that reusable rockets are fundamentally less cargo per trip than non-reusable ones, since the reusable rockets have to carry extra fuel for re-entry. The sweetspot of having enough mass to orbit so that this reduced capacity is still worth it is not at all easy to reach.

In general, if rocket building costs could really be reduced to almost nothing, reusable rockets would be useless. The only case where reusable rockets have a chance is if building rockets is still very expensive.