And, this may not surprise you, but in January 2017, Google
announced that page speed will now be a ranking factor for
mobile searches.
In that same month, Google stated it will begin to devalue pages
with intrusive pop-ups.
In July 2019, mobile-first indexing was enabled for all new
websites. And, by March 2021, all websites will have switched to
mobile-first indexing.
20 YEARS OF SEO: A BRIEF HISTORY OF SEARCH ENGINE OPTIMIZATION