All coins are pretty terrible. When the US was trying to push those dollar coins, there was an argument that the government would make money by selling the new coins (through seigniorage), but that argument was counteracted by the fact that people just wouldn’t use those coins and it would end up sitting in a jar somewhere rather than in a bank earning interest (the velocity of money would be reduced).

The government should put less money into designing and minting/printing new money and instead focus its resources on making the “unbanked” banked. Doing so through the post office has been talked about for years.