Using a mouse can be impossible or extremely difficult because of either visual or mobility challenges. When giving directions on how to locate something, be sure you're not only describing how to get there using a mouse. "Click on the blue button at the top" implies someone is using a mouse and, can see to determine what is blue and where the top is, and that everyone is on a device where that button is always in the same location. "Select the button labeled 'Support'" is more universally applicable, and is instructive regardless of navigation type or device.