With the support for the newly-discontinued Windows 10 Mobile devices set to end on December 10th, 2019, Microsoft will be recommending that it’s current Windows 10 Mobile customers to move to an Android or iOS device instead. Microsoft also made the recommendations in a Windows 10 Mobile support document (according to Thurrott), in explaining that it’s plans to stop offering security updates and patches for Windows 10 Mobile.
With Windows 10 Mobile ending it’s support, we recommand that users move to a supported Android or iOS device. Microsofts own mission statement to empower every person and every organization on the planet to achieve more, compels us to support our Mobile apps on those platforms and devices.
Microsoft then ended support for Windows Phone in July 2017, and they also stopped the active development on Windows 10 Mobile in October of that year, leading to the death of their platform. Microsoft pretty much struggled to get app developers to write apps for their devices, and it was also never able to establish a strong user base.
With the completely abandonment of Windows 10 Mobile, Microsoft has mainly been focusing on other platforms and they also have a wide variety of apps available for both iOS and Android.
All of the customers that have Windows 10 Mobile will be able to keep using it after December 10th, 2019, though no further updates will be available from there.