Fair points, but you are glossing over important issues:

1. You are using the current point-in-time cost for batteries as compared to a subsidy spent over years while battery costs were dropping.

2. You do not include transmission upgrades and costs to distribute energy from centralized batteries.

3. You ignore the benefits and efficiencies of having generation and batteries distributed and close to the source of demand. It also increases resilience of the grid.

4. You assume the political will was there for government and taxpayers to bear the full cost burden of development of the batteries.