Why can not we say that human society has already entered the era of the noosphere?

Only a highly educated society can come into the era of the noosphere, understanding its goals, able to balance its needs with the possibilities that nature gives it.
For the rational management of the biosphere and the transition to the level of the noosphere, it is necessary not only to know the structure and principle of the “work” of this huge and complex system, but also to be able to influence the processes occurring in it in the desired direction.
At this stage, this has not yet been implemented.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.