Football boot uppers (the part on top of the boot) are made of three main materials, leather, synthetic and knit. Some boots even use a combination of two different materials especially involving leather. I will be trying to compare them as objectively as possible as I have actually worn every material myself.
Let’s start with leather. Leather was the original material in a football boot and was what all football boots used to be made from. A leather football boot will provide a very comfortable fit, where the leather will eventually mold to the shape of your foot. I say eventually because leather does take some time to break in. in terms of touch on the ball, a leather boot will provide a slightly padded sensation and the more leather the boot has the more padded it will feel.
However, one of the downsides to leather is that compared to the other two it is comparatively heavy. The heaviest football boot on the market is around 310grams and the lightest is around 190g meaning a total weight difference of 240g across both feet. Now that doesn’t seem like a lot and it isn’t, but it also means that they are generally not marketed as light weight “speed” boots which is what a lot of people want.
Generally speaking, leather boots are also a good option for players with wide feet, This is because as mentioned above leather tends to mold to your feet over time. This also means that they will stretch and can even stretch up to half a size. This is good but it as well has downsides as sometimes the boots can over stretch leading to a total lack of responsiveness and even blisters because of how much your foot is slipping inside.
In terms of durability, leather also has downsides. While the overstretching can lend the boots to being unusable. The softness of the leather can be in some circumstances be prone to tearing or wearing away faster than other materials. Now, you can prolong the life span of a leather boot by properly caring for them with some leather balm, but this adds to the cost of owning a leather boot and most people including myself can’t really be bothered with it.