I think continual Turing testing is the only way of concluding whether an agent exhibits intelligence or not. Consider the philosophical problem of the existence of other minds. We believe other humans are intelligent because they consistently show intelligent behavior. Things that people claim to be examples of AI right now lack this consistency (possibly excluding a few very specific examples such as AlphaZero). It is quite annoying to see all these senior researchers along with graduate students spend so much time pushing numbers on those datasets without paying enough attention to the fact that pushing numbers is all they are doing.
[1]: As a concrete example, consider the textual entailment (TE) task. In the deep learning era of TE there are two commonly used datasets on which the current state-of-the-art has been claimed to be near or exceeding human performance. What these models are performing seemingly exceptionally well is not the general task of TE, it is the task of TE evaluated on these fixed datasets. A recent paper by McCoy, Pavlick, and Linzen (https://arxiv.org/abs/1902.01007) shows how brittle these systems are that at this point the only sensible response to those insistent on claiming we are nearing human performance in AI is to laugh.