Boeing is on the glide slope
The evidence of the past several decades is that Boeing has lost the recipe for managing complex engineering projects.
The problem began during the Reagan era, when Boeing won much more business than they could cope with. They were slow on some and others were terminated for the convenience of the government, but no lessons were learned. A decade later, they won a huge NRO contract for Future Imagery Architechture, to follow on to Lockheed's existing spy satellites, which they failed utterly to produce. The only hardware from this multi billion dollar disaster are some telescopes that the NRO has recently gifted to NASA.
Since then, we have had badly delayed efforts such as the Australia Wedgetail radar surveillance project and the Japanese and Italian KC versions of the 767, also many years behind schedule and low on performance.
The 787 in other words shows performance in line with recent Boeing developments. It is not an exception and quite possibly the current battery/electrical system problems are only a symptom, rather than the real problem. Boeing used to respect engineering and flourished because of it, imho. Now it is increasingly outsourcing the engineering because it respects primarily financial returns. We will see how well that works over the coming years.