Despite its theoretical nature, Deutsch's proposal has faced significant criticism. For instance, Tolksdorf and Verch demonstrated that quantum systems without CTCs can still achieve Deutsch's criterion with high accuracy. This finding casts doubt on the uniqueness of Deutsch's criterion for quantum simulations of CTCs as theorized in general relativity. Their research showed that classical systems governed by statistical mechanics could also meet these criteria, implying that the peculiarities attributed to quantum mechanics might not be essential for simulating CTCs. Based on these results, it appears that Deutsch's criterion is not specific to quantum mechanics and may not be a good way to figure out the possibilities of real-time travel or how quantum mechanics might make it possible. Consequently, Tolksdorf and Verch argue that their findings doubt the validity of Deutsch's explanation of his time travel scenario using the many-worlds interpretation.