First of all we will see all the terms what that means:-
At this time when I am writing this answer fleet is effectively dead. CoreOS has abandoned it in favour for Kubernetes. So the answer is yes, there is an advantage of running Docker and Kubernetes instead of fleet. You must have a look in order to learn about all these things in details and also want to learn Kubernetes and to have a decent and valuable certificate then you can visit Intellipaat Kubernetes Training course. If you like to read the concepts than you can read the following Kubernetes tutorial. You can also watch the video tutorials free of cost on Youtube visit the link mentioned-below:-