Lens was built for the person who stares at an element on their site, knows it looks wrong, and has no reliable way to figure out why.
The CSS visibility gap is specific. You can see the problem. You can describe it. “The button color is wrong.” “The text isn’t centered.” “This section has extra space that shouldn’t be there.” What you can’t see is what the browser is actually applying and why. You might have written a CSS rule that you thought would fix it. The rule might exist. The problem might still be there. And you have no way to know whether your rule is being applied, overridden by something else, or ignored for a reason you didn’t anticipate.
Lens is for the WordPress site owner who edited a color in the Customizer and the page is still showing the old one. It’s for the Squarespace user who can’t get a font size to change no matter what they try. It’s for anyone who has opened DevTools, looked at the wall of properties, and closed it again because it wasn’t answering the question they were actually asking.
You don’t need to know what “specificity” means. You don’t need to understand the cascade. Click on the element that looks wrong, and Lens tells you what’s actually controlling it and what to do about it.
Lens works on any website in Chrome. If something looks wrong and you can’t see why, Lens is built for you.