We had a similar thing in Australia - the Australian Government Design System: https://designsystem.gov.au/

It is in use across a huge number of Australian government websites - the Australian Cyber Security Centre, Services Australia, Department of Health, Department of Veterans' Affairs to name just a few.

The agency that owned it had a huge amount of funding cut from its budget, and now it's being supported by an (admirable!) open source effort: https://designsystemau.org/

It's wonderful that there is this level of community support, but so disappointing that the government couldn't recognise the importance and usefulness of continued funding.