First of all, I should mention that one of the biggest critiques of Marco Polo comes from Frances Woods, Did Marco Polo Go to China? Among other glaring issues, Polo never mentions the Great Wall of China and a number of other items that one would expect a visitor to mention in an extensive account.

The other issue with the text is it's Frankenstein manuscript tradition. The Travels were copied down so many times with different stories, it's hard to know what's original and what is not. I was in a seminar in which we discussed Marco Polo and a friend wrote a paper about the elements of romance literature found in the text, suggesting that elements of Polo's account should be seen more as literature rather than a straight up travelogue. Indeed, the Rustichello da Pisa, individual who actually wrote the thing based on Polo's supposed recollection, was an author of romances.

Perhaps the most convincing version is one written/copied by a Monk that is more of a list of events rather than any sort of Romance.

In my personal opinion, unless someone provides a significant recounting of the manuscript tradition coupled with reasons why they are using specific elements of Polo's account, The Travels barely meet the requirement for valid historical evidence for the Mongolian Empire. There are a number of (admittedly problematic) European accounts of the Pax Mongolica.

The Travels are much more useful for understanding how medieval Europeans saw the world. Its popularity means that we can use the text to reconstruct how medieval Europeans saw their place in the world.