Of course, phantom time is just a hypothesis. Beautiful, interesting, mysterious, but with a high degree of probability incorrect. For each argument given in favor of defending the hypothesis, a counterargument can be made. For example, the construction of buildings in cities was suspended due to the outflow of residents from them, which occurred as a result of ruptures in economic ties between regions, and the return to ancient culture, even after 5 centuries of inactivity, can be explained by the lack of their own basis - architects had to start somewhere. Yes, and the same radiocarbon dating method has made significant progress in recent years, adding to its arsenal calibration by the decay of thorium in corals, by glacial layers, by clay band deposits in lakes, which made it possible to confirm the correctness of today's historiography with even greater confidence. In addition, in addition to radiocarbon analysis, there are dozens of other methods for dating historical monuments and artifacts that give approximately the same result. One could also refer to the Muslim chronology of that period, but here the situation remains inaccurate - some dates here coincide well with European ones, while others differ so much that the explanation of the introduction of an additional three centuries even begins to look a little logical.
Ultimately, whether the phantom time hypothesis is true or not doesn't make any sense. After all, no one will turn back time and reprint history books. But for enthusiasts eager to uncover the truth in the ornate historical chronicles, the phantom time hypothesis offers ample room for study and debate.