A registry back up is exceptionally useful. If your system runs into problems, the registry back up can help restore it to a stable state. It is therefore mind boggling that Microsoft would turn it off. The reason the company has given for turning it off is that it was meant to save space (about 150MB).
Microsoft doesn’t announce all the changes it makes to Windows 10 when a major feature update is released. Some minor, and occasionally major changes aren’t mentioned at all and it isn’t until users go looking for a particular feature, item, or folder. Microsoft disabled registry back ups with the 1809 update and never mentioned it. The feature has been disable but not removed which means you can enable Registry back up on Windows 10 1809 and later.
See how at https://www.addictivetips.com/windows-tips/enable-registry-back-up-on-windows-10/
#microsoft How to enable Registry back up on Windows 10
How to enable Registry back up on Windows 10