Google

Way back in November 2016 Google first announced that it had begun experimenting with mobile-first indexing. Its reasoning was pretty sensible: if the majority of people are using the Google search engine on their smartphone or tablet, it makes sense that the web page the algorithm evaluates is the version that they are seeing.

Mobile-First Indexing: Should You Be Worried?

Way back in November 2016 Google first announced that it had begun experimenting with mobile-first indexing. Its reasoning was pretty sensible: if the majority of people are using the Google search engine on their smartphone or tablet, it makes sense that the web page the algorithm evaluates is the version that they are seeing.
Google