Powerpoint can be used for techical talks. Similarly, PowerPoint is also used for two things. One is for technical talks. For this purpose, slides should be almost entirely pictures, with only a word or two per slide. What you say it over it is important, but the illustrations/Powerpoint should be all pictures. You should follow the rules.
Some people want you to use Powerpoint to make an illustrated precis. The second use evolved because, occasionally, your adviser, boss, program manager, or Dean will say "Quick! Send me three slides on your research as soon as possible!" Perhaps they don't understand much about your research and probably can't present it. So for this purpose one might be tempted to make slides as dense as possible, containing lots of tiny cryptic text and information because basically your Dean is going to have to try to read them. They're going to be more like a Dadaist Powerpoint collage of your papers. So this is a totally different purpose from a good technical talk. And the slides look totally different. These 'boss' kind of slides are completely inappropriate for a technical talk -- mostly because they are covered with words that you don't need as the author of the research -- you already know how to say these words -- and so they are much more cluttered and jumbled. Also, there are usually way too many things on these kinds of slides, because your boss only wanted three slides. In an hour-long technical talk, you could have 20-30 slides easily, and follow the doctrine.
Some funding agencies are notorious for asking for these cluttered slides, i.e., for essentially an illustrated precis. The problem is the second kind of slides make terrible talk slides. Because they violate the dogma -- they are too cluttered, they have to many words, and too many concepts on the same slide. (* But see below for a better solution.) Since it takes a lot of time to prepare slides for your boss, you might be tempted to re-use them in your presentations. Don't. They will ensure you give a terrible talk. It would be like sending in a list of search engines, instead of a list of publications, when emailing your CV for a job application.