That would be typical, take ownership of another team's pet project, block that team from contributing further, take all the credits from management and let the project die. Seen it happen multiple times at my current gig.
Happened to my personally at the gig I recently quit at. I thought I was the only one.
The trick is to make your own dashboard but not calling it a dashboard. When they try to stop you, claim that it is not a dashboard (even though everybody knows it is a dashboard). Insist that they define, in writing, exactly what a dashboard is. Continue rejecting their definition with counter examples. Insist that the definition is unclear and needs to be defined in a formal language. Reject their formal definition after spending months being “too busy” to review it. Change the background colour/font/title and claim that it is changed so it needs to go through the review process again. Ask for their written definition of their review process. Insist that it is ambiguous and needs reviewing/fixing. Repeat forever.
You've clearly played the game
When in Rome behave like the Romans :)
If news spreads out that you can do things on your own, the dashboard team would lose its power and budget. Dashboard team has probably done it for years, they have a safe job: everyone needs dashboard and everyone needs to go through them. They can keep their annual budget and since the upper management probably has no vision they don't have to invest time, effort and take the risk to create a self service platform. A global optimum might disrupt a local optimum and they will fight against it.