I disagree garaa can make the location he is a desert with no chakra easily like what he did with kimimaro ad btw the location it's normal place not desert not water just a normal green land but gara can make a desert with no chakra soo the location dosent really matter
Sure he can do that, but it can only work for one moves or 2, when in his desert he can take advantage of the huge quantity of sand anytime he needs. But whatever, you can say what you like, but battlefield does matter in Gaara's case. If they fight on water, Gaara is screwed. His battlefield changing ability won't work there since he needs to turn the minerals and rocks into sand to be able to do, what he won't able to if he is on water. On the other hand, Kakashi has dangerous and huge suiton attacks such as
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that Gaara could most likely not defend himself against and even if he manages to, his sand would become useless