Mobile-first indexing on Google will be complete by September 2020. This means Google will use your website's mobile version when deciding ranking. On July 1, 2019, Google started mobile-first indexing with new, previously unindexed sites. There is only one index, not a separate mobile index. For people who don't have a mobile version of their website, Google will use the desktop version.
Anyone who has a separate mobile site with less content than their desktop version can expect to drop in the rankings. Both sites should have the same content. Both sites should also have the same META title and description as well. Your desktop and mobile version should have the same headers. If your site is responsive, you don't have anything to worry about.
Most searches are done on mobile devices so Google wants to provide the best possible experience. They have been talking about mobile-first indexing for several years now so there is no reason for webmasters not to be ready. There's no way to know when your site will start sing your mobile version, if they haven't already. You can't speed it up or opt out.
If your website's mobile version is indexed, it does not mean it is mobile-friendly. It's up to you to make sure your visitors on mobile devices have a good experience. Responsive sites adapt to the user's screen size automatically, making them a good choice for webmasters who don't want two separate sites.
In 2018, over 60 percent of searches originated on mobile devices. Searches for food or beverages topped the list. presumably from people looking for a nearby restaurant or bar. Local businesses usually understand the importance of having a mobile-friendly site, but there are still a few site owners who believe their users mostly access their website from a desktop computer. For more information click here https://searchengineland.com/google-to-switch-completely-over-to-mobile-first-indexing-by-september-2020-330174.