In these "post-singularity" times it's hard to speculate.
I think it's unfair to cherry-pick one task attempted by a cost-aware electricity company, that didn't involve the majority of humanity, and judge humanity on that basis. The nations best and brightest where not called upon to hang power cables.
I just don't see a post-human future that is based on silicon: the manufacturing process is far too complex and poisonous to be viable as a self-replicating system and it doesn't last long either. I don't see a biological post-human civilization being feasible either: we've all but depleted all easily accessible natural resources, so any new civilization would have an uphill climb to surpass our technology.
People talk about Dyson spheres but for some reason no one mentions that space debris will puncture every material known to humankind because it's just flying so damn fast. Seems like a fairly obvious and fundamental physics issue IMHO; not exactly something that one can just wave away with theoretical future technology.
Maybe you know something I don't, but as far as I'm concerned, space colonization feels more like wishful thinking than something that could actually realistically happen.
> also quite a fundamental piece of technology
I don't think long-term cable maintenance is considered important; whether a technology exists, and whether it was provided (at cost) is different. In most cases the electricity companies where obligated to provide maintenance to small communities, without profit, so did it on a least effort basis.
> I just don't see a post-human future that is based on silicon: the manufacturing process is far too complex and poisonous to be viable as a self-replicating system
I didn't say anything about self-replication; but AI controlled hardware could be self-replicating/sustaining in exactly the way human society is. In the meanwhile, If a sufficiently flexible robot can be remotely controlled by human operators, what stops multiple robots maintaining each other?
It really isn't a stretch to posit that an alien form with liquid-methane-based chemistry (instead of water-based) would want to stay far far away from places like Earth, just like we wouldn't like to sunbathe in Mercury. And the boring but most likely occam's razor of alien civilizations is that it isn't actually physically possible for a civilization to leave their home star.