Producing fruit requires a lot of
energy and resources from the tree, and as trees get older and bigger they require more resources to support their size. If there aren't
enough resources, the tree will skip producing fruit, and focus its energy on more necessary things. Increasing the soil health and organic matter should greatly help to increase fruit production. A good leaf mulch will break down into super rich, moisture retaining soil, giving the tree what it needs to produce a good crop.
Lots of vertical growth can be a sign of too much fertilization or also a result of over pruning. Some varieties just like growing more vertical though, and will do so no matter what. You can bend some of the branches down, which will encourage earlier fruiting and discourage vigorous growth.
Good luck with your fruit trees!