The middle man in centralized energy production is more than just the grid. It includes the power generators, the fuel providers, the waste disposers, the transporters and so-on.
No, power plants are the primary producers of the product you are producing, the middle man is the term used to describe the intermediary through which you purchase the product at the point of consumption. And that is whoever owns the grid.
All of these will seek to make as much profit as the market will bear. Add on regulation and inspection as additional costs.
The cost of the grid is heavily regulated because it is a monopoly by nature of being a utility. There isn't really an electricity market, there's one grid that you can buy from and the power company can't gouge you. And besides, do you think that there aren't steps to generating solar panels and hooking them up to your house that people won't seek to profit from as much as possible? All of these will seek to make as much profit as the market will bear.
Solar can be stored on site for use at night.
Not without an incredibly expensive and inefficient energy storage medium.
It can shared with neighboring properties without needing a grid.
Um, no. The interlocking of peoples power supply to a single collective network is a grid, by definition. But also let's consider this problem. Let's say all your neighbors own solar panels on their homes but all of the electricity generated by them can only be shared in a neighborhood wide private grid. Well, since they all live in the same area they all get roughly the same amount of solar power because the sun will shine similarly on all of them. Well if one house is generating more than enough electricity for its needs then chances are their neighbors are as well. So they CAN'T share their electricity with each-other because they won't need it. But the LARGER electrical grid can send that power to the large buildings that use way more energy than your home could ever produce and more energy than their building could ever gather by covering it's surface in solar panels. The larger business community are the only ones who are going to have a need for that extra power that you still don't have storage for because, once again, storage is just completely impractical right now. The name of the electrical game is use it or lose it, so your desire to unhook from the grid is leading to you willingly allow your home to piss energy into the wind.
The public accepts them willingly.
Which, once again, I accept and it makes me happy because they replace SOME dirty fossil fuels.
They have improved relentlessly and consistently over decades and so they will continue to improve over decades to come.
No. Like all technologies they usually hit an innovation plateau in their niche. All of the easy to find discoveries regarding producing solar energy with greater capability and cost efficiency make it experience an exciting exponential growth in capability. But oil and coal have experienced the same sorts of booms and they plateaued out and still innovate but not as fast as they used to. There's no reason to assume that solar is an exception to this general rule. And it doesn't really need to because it is already starting to out-compete coal and other dirty shit for cost. What needs to be improved is energy storage technology, in cost and capability efficiency, in order to make solar a viable backbone for the energy sector of our economy. And that technology is wholly separate from solar panel technology.