Tesla has economies of scale because they manufacture more or less the same equipment globally. They are passing less money to suppliers. And they have more technicians going around so they can use connectors that are replaced more frequently. They don't have screens and have starlink for backup comms and car comms. When they lose connectivity with the mothership they charge at full speed for free.

Regardless of that, if thier costs are the same, by asking for less money for more outlets they are more likely to get money. When you show you're willing to put up your own cash or just ask for less money in general while offering equal or better performance, you're more likely to win bids.

Politicians prefer to say they brought 10000 chargers than 4000.

The subsidy request is just you asking for money and doesn't represent your costs just what you want to ask for. You can ask for more than you need i.e make a profit on building costs

The question is how much do you want to do this, not how much will it cost you