The DTA design system was designed to do exactly that across federal government. However it isn’t resourced sufficiently to keep pace with dozens of design teams, and those design teams are not contributing to the maintenance of the central design system. If the states wanted to field people to help maintain this design system, I’m sure the DTA would be keen to have their help.
The issue is, each design team is resourced to maintain their own designs, they create design systems because of an internal efficiency. No one is being paid to manage pull requests from other departments and resolve design issues for other agencies.
Lets say you design a component to solve a business and user need for your agency, you release it publicly, but now another agency needs you to do a heap of work to support a use case you’ll never have. Is your executive really going to redirect you from their pressing priorities to support that other agency’s use case?
The long term cost saving is cross jurisdictional and hard to quantify, the short term cost impact is significant and easy to quantify.