I found the OP’s example perfectly clear, too, although “the basis for greater efficacy” is a tad wordy.
There is nothing wrong with the passive voice when the agent is unknown or immaterial.
The real problem with a lot of writing is the use of nouns instead of verbs, i.e. “take into consideration”, “make a determination”, “have the intention”, instead of “consider”, “determine”, and “intend”.
And introductory qualifying phrases, but that might just be me.
Would 500 lawyers and 500 scientific researchers with 1000 typewriters, given an infinite amount of time, actually write anything comprehensible to the ordinary human being?