If you've ever gone into a shoe store and had problems finding a shoe that fit both your feet correctly, I'm sure you've considered custom shoes; something that didn't pinch in just the wrong place or require an extensive break in time that broke in your feet to suit the shoes more than the other way around.
Individually made shoes are hard to find now. Mass produced shoes are so much cheaper to manufacture, the rarity of cobblers who can make custom fit shoes is combined with the barrier of having tailored shoes produced being a terribly expensive privilege per pair.
Handmade sandals crafted of leather are an affordable possibility. Since leather is simpler to work with and sandals don't require as much of it as oxfords or loafers, they naturally do not cost as much. They can be cut from shoemaking remnants or can be made with even less waste if the fabric is cut especially for them. That makes them an ecologically responsible option.
The use of custom leather for sandals is a natural choice. Custom leather is long lasting and durable, but it is also soft and breathable. When wearing leather sandals, you will find the strips of leather are softer and can conform to your foot more readily than tough woven fibers and man made materials, which you must often force your foot to conform to.
Obviously, sandals are best suited for use by those who live where it is warm much of the time. Wearing sandals may make your feet feel cooler and they may be more susceptible to becoming dirty as opposed to conventional shoes, but they can be adapted to suit your orthopedic requirements. Because sandals allow air to circulate around your feet more easily, such problems as athlete's foot and some types of toenail fungus may no longer be a problem.
Leather sandals obviously don't fall under the category of vegan, but they do help ensure that every part of the animal is used. Killing an animal for food while leaving the hide, a fairly large part of the animal, to go to waste is a bit foolish. Sandals don't create a need for slaughter, but they do create a use for a part of an animal that would otherwise be wasted, which means fewer animals are being killed for the same reasons.