Trying to fit a large flow chart on a single PowerPoint slide is harder because you have to play with fonts and it's harder to scroll around on the page when you have it zoomed up.
But, did you know that Excel also has some of the same Drawing tools as PowerPoint and Word? Not only do you have access to the same set of tools, but take a look at the following reasons to use Excel: Why use Excel to create a Company Organization Chart? If you've created an organizational flow chart or other types of flow charts using PowerPoint, you probably know how frustrating it can be to constantly move around, resize, and align various blocks.
How to Create an Organizational Chart in Excel