Oddly enough. I found ChatGPT to be good at making slides. I prompt it with the text I want and some "stage direction" about the aesthetics and it makes good slides. It also makes good PDF documents as well; I feed it my markdown and tell it to make a publish quality PDF and it does a good job. In short, I am defaulting to Obsidian/markdown and use ChatGPT when I need to create other formats.