Set the font size for the complete page in Power BI
As we know one page consists of many visuals, to change the visuals visible in one go, we going to increase the font size. Instead of setting the size of each visual, we will change the setting at the page level. As shown below the page has less visibility:

We change both visual font sizes in one go, By Going to the View tab as shown below. Select the highlighted button-down arrow key:

Next, choose the customize current theme option

Go to the TEXT tab and change the font size on the right side. At last apply changes will modify the complete page font size.

Now both graphs will be modified as shown below:
