I was pretty fortunate that my Army job rarely had any PowerPoint presentations. In fact, the first time I saw PPT was during my tour as a recruiter. This was in the mid-90s. Our recruiting battalion was the first to be issued laptop computers to assist in our sales presentations. We had proprietary videos and such. We also had Microsoft Office, but there were no prepackaged PPT presentations. I put together a few to back up the information I wanted to present.
In my civilian job, making presentations was a huge part of my daily duties. My boss very rarely did a slideshow, however. Mostly we used printed and bound slides as a leave-behind to reinforce what his sales pitch was.
I think that is the key to using PPT effectively. Many people use PPT as a replacement for a proper presentation, rather than a tool to reinforce the main points they want to make. One of the reasons this is so frustrating is that over many years, the services have developed ways to effectively communicate complex plans quickly through a format that is universally understood (such as the 5-paragraph operations order) and then promptly sets these methods aside for a slideshow.