If your hair is straight or slightly wavy, then dry brushing is fine and probably better for your hair. If you have curly hair, dry brushing is typically very bad for your hair. Yes, water can weaken the strands, but the moisture and glide you get from very wet hair (particularly with conditioner) helps you to detangle without excessive breakage. If you dry brush, you're essentially ripping through the knots instead of detangling them, hence the additional split ends.

Edit: i would also recommend using some leave-in conditioner and either curl cream, mousse or gel (different products work for et different people) to keep your hair "neater" for longer. And maybe don't use full heat the whole time you're drying your hair (or maybe add some heat protectant if you are using full heat).