I say this because when the Spanish come to conquer the Americas there were so many new things to the Aztecs. Even though if the Aztecs were left alone and they started to trade with other countries there would be so many new things to the Aztecs that they wouldn’t be able to keep up. But that would be assuming that they did start to trade and that they didn’t get rejected. The Aztecs may have gotten rejected by other countries because they were very demanding and they may try to take the country under its grasp.
Another thing is that if the Spanish had left the Americas alone I believe that the Aztecs weapons would’ve evolved near the end which would leave them open to other nations like the French or English. If the Spanish hadn’t come to invade the Americas the Aztecs never would’ve saw gunpowder, horses, cannons, iron armour, swords, ships and lancers. Without the Spanish invasion the Aztecs would’ve been extremely vulnerable to other explores and they probably would’ve got conquered by another faction of