Android uses a modified version of the Linux kernel; it depends on the Linux kernel project. According to Statcounter, Android has about 72% global market share on smartphones, with iOS at about 28% [1].
Many websites and web services run on Linux, at least in part. Wordpress, the most popular CMS, with around 63% market share [2], can run on other OSes, but it's usually run on Linux.
Linux is now more used on Azure than Windows Server [3].
Linux is also used in lots of other everyday things, e.g. automobiles, microwave ovens, routers, etc. You get the idea.
[1] https://gs.statcounter.com/os-market-share/mobile/worldwide
[2] https://w3techs.com/technologies/history_overview/content_ma...
[3] https://www.zdnet.com/article/microsoft-developer-reveals-li...