Weeping Cherry Oozing Sap
What you are seeing is a weeping of sap which is called gummosis. It happens whenever bark is damaged somehow. In this case it is likely a boring insect that commonly does this. The tree pushes out the sap to try to expel the intrusion.
Once borers are in a tree there is not much you can do.
Here is our page on boring beetles: https://www.extension.umd.edu/hgic/topics/borers-trees
It usually leads to scattered branch dieback over time, but it can take years and years to kill the tree outright. People often remove them once they lose the attractiveness they had sought. On the other hand, I have one in my backyard that the birds use to get to my bird feeders, and the dying branches are a great draw to more than one type of woodpecker.
Ornamental fruit trees themselves are not long lived. Maybe 15-25 years before they begin to decline.