I create a web site in MVC 5. When I hosted it's kendo.min.js file size is 3.67MB. I Tried Both CDN and Static of Kendo js file. But no bigger difference come. MY site performance is at F grad. 47% uses of kendo.js file.
This is usually happening, if you use kendo.all.min.js, which, as the name suggests, includes all functionality, widgets and kaboozle.
You can always create your own bundle by just using kendo.web.min.js and kendo.menu.js, based on your needs.
A good starting point is the documentation here: https://docs.telerik.com/kendo-ui/intro/scripts/what-you-need