Supply chain management is a complex exercises. It takes a lot of time, trials and errors, reviews and alterations of tactics to find the right strategy. You should not make random changes to that strategy unless it is absolutely necessary. Many companies have proactively and voluntarily tried to transform their supply chain management strategy and in the process have adversely affected a perfectly functional apparatus.
One of the reasons why avoidable changes are best avoided is to ensure sustainability. The sustainability of a supply chain depends largely on the reliability of various players. All suppliers get into a rhythm when they constantly provide the materials they are entrusted with and deliver them in a manner they get accustomed to over a period of time. Any substantial change can threaten to disrupt that rhythm. There is a reason why so many companies across industries took a long time to switch from analog to digital modus operandi. Even today there are companies that want to digitise everything but are still holding onto some seemingly archaic practices of the bygone century because they ensure continuity and sustainability.
Supply chains are always vulnerable. There is no perfect supply chain as something or the other can always be improved. The definition of perfection also changes with time as technology transforms the idea of efficiency among other changes it ushers in. If there is a problem or you find your supply chain management strategy to be ineffective in some regards, then you can always address those problems but leave the rest of the apparatus unaffected. One sweeping brush stroke is often not the best way to make structural changes. Any apparatus that has too many players and hence possible variables should be meticulously addressed, whether for improvement or to fix any prevailing issues and the changes conceived should be thoroughly assessed before implementation.