While Microsoft has moved on to much newer versions of the NT kernel, you will still find 1809 1.3 in use within:
This was the kernel version that first introduced the DirectX Raytracing (DXR) API, paving the way for modern gaming visuals. kernel os 1809 1.3
The 2019 version of Windows 10 LTSC is based on the 1809 kernel. It is prized for having no bloatware, no Cortana, and no unnecessary telemetry. While Microsoft has moved on to much newer