Long-term planning on a colossal scale (like nation-state-level) (or even on a not-so-colossal scale - think of how many plans YOU have made and how they turned out) is pointless because of black swans
Sure, having a general idea of where you want things to go is fine, and everyone already does that; but when a government starts thinking that they should set a concrete goal X and they should do Y to achieve it, it's just akin to trying to predict the future, and we all know how well that always works out, because theyre under the faulty premise of thinkin Y will be constant forever, or that even the goal itself (X) should remain constant in a world that is anything but constant
So, this is a terrible argument for not having elections, or bigger election cycles. I'm sure someone could potentially put forward a better argument, but this one is not it
"Plans are worthless, but planning is everything." (variously attributed)
Definitely not advocating for "not having elections, or bigger election cycles" BTW.
I think the way that democratic governments can achieve these long-term plans is by establishing (or using existing) entities to complete these goals on their behalf.
An example that comes to mind is the Apollo program: JFK announced a national goal to land a man on the moon in 1961 and this was finally achieved in 1969 - two presidencies (Johnson, Nixon) and one change of party (Dem->Rep) later - with NASA being that independent responsible entity.
Yes, but this sort of thing seems increasingly unlikely in an ever more partisan world. Especially when would-be autocrats are wrecking as many institutions as they can.