Microsoft Word format vs Better Proposals format
All the documents you create in Microsoft Word are centered around the concept of a piece of paper. What you're essentially doing is trying to fit your content and graphic elements onto a page. And while this is great for printing purposes, it's not the best option for digital use.
These days, most clients open and view documents on their computers and phones. Since the documents you send represent your business, you want them to help you make a good first impression. With Microsoft Word, you'll have a harder time achieving it than with Better Proposals.
MS Word documents aren't responsive
As already mentioned, a Word document is essentially a digital piece of paper. Its size is fixed, meaning it doesn't adapt to different screen sizes. For that reason, no matter how much time you spend formatting your Word document to perfection, there's still a chance it won't look as professional as you wanted it to. And while you can't control which device clients open your documents on, you can control file formats you send them in.
With Better Proposals, your documents work like responsive web pages. This means that, no matter the device your clients open them on, the design and formatting always adapt to the screen size. That way, you can make sure your always clients see exactly what you wanted them to.