It has very little to do with the glue. It is more about how the models are looked after. We have two sailing ships that I built over 30 years ago, and they are still OK. They are kept on a shelf where direct sunlight never shines. Look at these two photographs, one of a model as completed, and the other ten years later. When they brought it back for repair, I said "You've kept in in direct sunlight, haven't you!" and the confirmed that they had, saying there was no alternative. I eventually repaired it so it was at least presentable again, but told them if they stuck it in the sunlight again, it would soon go the same way. I have had three more models returned to me that suffered the same fate, but the majority are looked after properly
Bob