Sometimes the icon is the only way to tell what something means, like a status. Then give the icon itself a name. Adding aria-label makes it visible to screen readers. Add role="img" too, so every screen reader reads it as an image.
MEANINGFUL ICON
<WifiIcon role="img" aria-label="Connected to Wi-Fi" />
A few more tips
Make buttons big enough to tap. Aim for at least 44 by 44 pixels. Make the button bigger, not the icon.
Don't use colour alone to show meaning. A red icon and a green icon look the same to many people. Add text or a different icon.
Write the label for people. Say what the button does ("Close"), not what the picture is ("Cross").