Slightly different (possibly worse) situation but similar principle:
My brother-in-law just built in a semi-rural area near New Plymouth. He applied to the local lines company for a power connection and was told the transformer couldn't handle anymore connections. If he wanted to be connected he'd have to pay the cost of a transformer upgrade (~20k). This new transformer has capacity to supply more than just by BIL, so any future connections won't incur that cost, but he doesn't own the asset he paid for (he's obviously no liable for ongoing maintenance\repairs, the lines company does that once installed).
At least in your situation what you are paying for only benefits you.
My parents had to do that. They had to pay for a transformer for servicing 2 other sections as well as their own when they wanted to connect up to power, even though they don't own it. So they had to pay for a transformer that was suitable for servicing 3 sections. They were however told that when the other two sections got connected, they would be reimbursed for the other people should have paid if it was split 3 ways, so they were told the cost wasn't as bad as they thought it was. In the years that followed one of the other properties connected up to it, and they got a small payment back for that. However the last property decided to go solar instead because they didn't want to pay all the fees associated with connecting to the grid, even though long term it would probably work out cheaper for them, and more reliable. IMO that was somewhat selfish of them to do that because IMO they should have shared the cost of infrastructure with the other neighbors, and they were only having to pay a 1/3 of the price as well. But that sort of thing is likely going to become more common, and will likely cause fixed line costs to increase over time as more people go off the grid, and you have less people paying for the infrastructure.