Google announced in 2016 that they were changing the index algorithm to be more focused on mobile users. Well, the shift is officially happening in March 2021. If your site is not mobile-first ready, it runs the risk of not being indexed or blocked.
What does being mobile-first really mean?
The mobile version of your site needs to be as content rich and complete as the desktop version.
Do you need to be worried about my site?
If your site was designed or redeveloped within the last few years, you probably already have a “responsive” site. This means that it was built to accommodate desktop, tablet and mobile devices by wrapping and reformatting the content to those device sizes. If, however, your responsive site displays less information in the mobile version than in the desktop version, you may see a drop in indexing.
If you created a separate mobile site specifically for mobile devices (m. site) that is completely separate from the regular www. websites, indexing and subsequently traffic could drop significantly.
To read how to prepare your site, see FULL BLOG POST