I don't think the battery is the issue here anymore. I think the electronics can go out and your local Prius dealer does not repair them, he simply tests each modular component and replaces them at a cost of 1000 - $6000. On another forum, a poster said he was told he needed a new battery at a cost of 3K.....he had a friend who was an electronic specialist (non-auto) look at it and he found a corroded contact on one cell and fixed it with some soldering in less than an hour. Does not say much for the techs (if you want to call them that) at the dealership.
I expect the electronics to last as long as the rest of the car and to be completely outdated when it is time for the new one. I've read more stories here about traction battery failures than other electronic failures. Yup, electronics are expensive so don't fry them. The guy in the story you mentioned was lucky and as I remember it, they spent more than an hour on the battery. Diagnostic time doesn't pay. Swapping parts does.
When you said electronics, I was thinking electrical wires, electrical connectors and electrical equipment but not really the battery lol. I guess it is part of the electrical system. The battery is warranted for 8 years and 160,000km (10 years and 160,000 miles in CA emission states) so it'll last. (Our 2005 is still on its original at 11 years and 230,000km of mostly city driving). I expect the electronics on my 2010 to last the life of the car (that includes the high tech stuff like the radar unit and solar panels). I wouldn't order these items if I had bought a non-Japanese vehicle (call me bias if you must but my stint with a German car was not trouble-free and it had no fancy electronics, not even cruise control).
Techs at the dealer are limited by what Toyota says to do. There is nothing to be done to the battery. It is considered non-servicable by the OEM. Ditto modules. There are places which can repair them, but most places, and all dealers replace with new. Be thankful you bought a Toyota, where module failure is rare, and they are re-programable. Some manufacturers make the modules where they can only be programmed once. If you have a failure, and the OEM doesn't make it anymore...no used parts for you, and your 2005 car is now a brick on wheels. FWIW, 14 year old Prii are still all over the place in these parts, and sell for way more than any comparable 14 year old car.
2013 C2. Hopefully 10-15 years. My other car is a '92 with no electrical problems but there's obviously a lot more going on electronically speaking with a 2013 car.
I bought an Apple ][ in 1978, and I asked whether to turn it on and off every time I used it or leave it on all the time. Woz said that if I turn it off and on the thermal expansion should cause failure in 30 years. If I left it on all the time, charge migration should cause failure in 30 years. It is still fine, I still have it, although to be honest I use it less lately.
I give dealerships a pass on not troubleshooting down to the component level. Although they charge by the hour, they get PAID by the job and component level diagnostics can be tricky. Traction battery replacements done by the dealer have come way down over the past few years because people are discovering that the battery is connectorized, and can be replaced fairly easily by a motivated home mechanic. Market forces respond slowly, but they DO respond. Almost every major component in a Prius can be bought 'gently used' on the market. Or? You can just trade out cars every 4-6 years and live with a lifetime of car payments. Your call. FWIW? Over my five years of Priusdom I haven't seen a very high failure rate for the on-board electronics. I'm guessing that they're designed with a 10/250000 life cycle, so the statistics Ninjas will probably snap the chalk line somewhere in the 6-7 year time frame. You want a car to break often enough to keep your sales force happy, but rarely enough to keep your customers thinking that your car is reliable. Toyota is pretty good at this. If their dealership network were a little bit better, they would be WORLD CLASS. So.....Put me down for a MTBF of 7 years. YMMV
Most of the things that can go wrong simply cannot economically be diagnosed and repaired to the component level at retail shops. The needed equipment and technical expertise are very high, and the low level of demand per shop simply cannot support it. On the stuff I designed for a high price / high performance electronic test and measurement company, much of that work as reasonable only at the design center or factory. Other facilities would just swap boards. Once a bad component or contact was found, repair could be quite cheap and easy (in those days, of thru-hole R's and Cs and 16-pin DIPs.). The real cost was the expertise and equipment to find it, easily exceeding the cost of a board swap. I'm was an electrical engineer. The wires, connectors, motors, switches, incandescent lamps, etc., were 'electrics'. The modules, displays, LEDs, LCDs, etc. were 'electronics'. The batteries were 'chemistry'.
