It's six times what's available globally for "low cost" panels, and three times the "mainstream" price, which is driving the other system components you mention to lower prices. After all, you can power appliances from solar panels without any of those other things.
I guess, but single full size panels generally put out 30-50v, and efficient batteries are usually 48V, so you’d need transformers at least, and the strings coming to our house are generally 350-500V. Newer high voltage battery packs operate at 400V+.
Not to say it’s impossible to run a DC circuit at 12V or less, but wire is expensive, and lower voltage means thicker wire.
