Using the viewport meta tag the wrong way can hinder users with visual problems accessing your website. By setting maximum-scale=1.0, you are disabling the functionality to use pinch zoom on mobile devices, and forcing users to view your page a certain way.

The bad way:

<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0">

The good way:

<meta name="viewport" content="width=device-width, initial-scale=1.0">

Avoiding maximum-scale=1.0 allows your site to meet users’ needs and provide a better experience.