You are thus proposing:... I don't understand why there is IN THE LANGUAGE. Isn't it redundant?
I agree that something is lacking - I don't know why.You are, thus, proposing:
My German has not reached a level at which I can communicate.
To me something is missing there. For example, one might ask: Communicate with whom? It seems 'communicate' has a sufficiently unprecise meaning that you need to specify it. By adding 'in the language' or 'in it' you tie up the sentence's loose end.
Is there some reason you need to specify "with people?"Could I ask please? I have an idea. Can I express this problem as follows?
My German has not reached such a satisfactorily level for me to communicate with people in it.
Or don't you have any other suggestions with FOR?
My German has not reached a level at which I can communicate with people .
I communicate quite satisfactorily with both people and dogs and the level of my German is practically zero. That's why "in German" is helpful for making the meaning of the sentence perfectly clear."My German has not yet reached a level at which I can communicate satisfactorily."
To this educated native speaker and retired senior editor for the world's largest news-gathering organization, it looks wordy and redundant.