You can use your own fonts in draw.io to make your diagrams more interesting or to match the text to your company's corporate style guide. You can use any fonts that are installed on your computer.
Some fonts are created to provide a good output for specific character sets, at the expense of the Latin character rendering in that set. In draw.io you can, attempt to, use any font you wish. Select a shape(s), select the text panel on the right, click the font name, select custom and enter the [...]