Batteries can be made to last longer. I have a caterpillar tractor battery in one vehicle that I bought in 1985 that works just fine. It also cost about twice as much origonally. I know people with solar power systems whose batteries are 15 years old. A longer lasting battery is also, naturally, heavier, so there is a trade of.
The hybrid battery in the Prius stays between 50 and 80% charged, so it is never discharged or overcharged. It is also not a large enough battery that charging it from a 110v source would be that huge of a benefit.
The systems on the vehicle are certainly complex. I have generally done repairs on my vehicles myself, there is little that could be done with the Prius without connecting it to a diagnostic computer.