One question that will never end within the online art and design community is: “What brushes do you use?”
They seem like the holy grail—the answer to why that speedpaint looks so great or why that environment concept has such a gritty, grainy feel. In reality, learning how to make Photoshop brushes is more of a novelty than a necessity; the basics are what make your art great, not your brush. There’s no one brush that rules everything; every brush is just a tool. That said, you don’t want to be limited by your tools, and knowing how to customize your brushes to make them resonate with your style or meet important deadlines is a valuable skill to have.
Custom Photoshop brushes can provide all sorts of cool effects that save time and communicate an element faster. Instead of painting every leaf on a tree or rendering every scale on a fish, cloud in the sky, or plume of smoke wafting through the air, why not create Photoshop brushes with the right dynamics to automatically create what you need? It makes sense.
Especially for designers and professional artists who work to deadlines and whose iterative process is enhanced by speed. For example, the concept artist or keyframe artist whose primary goal is to visually communicate information rather than simply wow the viewer, there is no need to demonstrate your basic principles to the person who sends you your salary by sitting down and rendering every blade of grass. That's what a portfolio is for.