PowerPoint is a visual aid to your presentation. It shouldn't be used like Word, as somewhere to write lots of text. Good use of images will enhance your presentation. Images can help the audience visualise what you're saying and help them to remember it. The audience are there to listen to you talk, not read screeds of text (and they're certainly not there to listen to you read screeds of text). You can also use slide images as a prompt for what you're going to say next.
To improve PowerPoint's use as a visual aid, think about using images to replace text or support it. Instead of displaying numbers, why not think about using charts or tables to graphically illustrate what you want to say.
Here, a bullet point list of continents is replaced by a map with each continent colour-coded.
Here, a list of words and numbers is replaced by a graph showing the same information.
Here, a quote on a clear background is replaced by a quote next to an image that covers the whole slide.
(Note that Albert Einstein never said this - he never said a lot of things that are attributed to him)
Some general tips for including photos and images in your presentation:
Image: Seven continents Australia not Oceania No author provider CC BY-SA 4.0