The title property as well as the rest of the htmlAttributes that can be set to the html button work with the KendoReact Button, but the issue here is that the title is not present as a prop for the component. I added it and it is currently at a pull request and will be available in an upcoming release.
Nevertheless, I realized that when using the Button with the KendoReact ToolTip, the tooltip is not shown when hovering above the button text but only the button element itself. Therefore, I logged a GitHub item for it. You can track it here:
As a workaround, you can use the html button instead and set its className to `k-button k-button-md k-button-solid k-button-solid-base k-rounded-md` to have the same visual appearance: