I do believe that a high IQ standard for government officials is necessary for an optimally functioning society; however, in practice, there are too many factors that would make the system flawed such as, without limit:

(1) Social Skills - A substantial amount of highly intelligent people are poor communicators--not that they cannot get their point across, rather, they may have difficulty delivering information in a way that is comprehensible to commoners (i.e., the general public). Currently, most politicians either think of (or are introduced) ideas of some critical, societal change, and they have researchers and scientists to run the numbers/data for them while they deliver the results to the public.

(2) IQ test validity - While an IQ test does a very good job at measuring pattern recognizing/deductive abilities, both of which are essential for intellectually rigorous tasks, it does not measure things such as decision making, discipline, impulsivity, empathy, dedication, sanity, irritability, diligence, etc., all of which are necessary for functional leaders.

There are more, but I would just be expounding on things that I have already mentioned. Further, all of the contentions can be (and are) a part of the contemporary government system, I am simply just pointing out how such a paradigm shift would not change much of how things are run. Intellectual capital should be allocated, however magically possible, to the general public. Insomuch as the people make poor decisions, be they health, finance, etc., the inevitability of a suboptimal nation--which I am sure is what the purpose of an "iqocracy" would be to fix--will remain.