It's always been a janky and stuttery experience and the massive improvements in computer performance (CPU, SSD etc) have never managed to bring it up to par, you can see how much faster Word loads even on a simple document compared to Writer. It's been that way since before it became open source: Star Office made you look at its splash screen for a decent while back in the day.
A few things I could think of: the templates for presentations are less varied, less diverse, could look repetitive. With Office, you can make the most crazy designs.
That's it. LaTeX generates PDF presentations that work everywhere and look very nice, they even have navigation buttons on the corner.
I wonder if we could teach ChatGPT to create LaTeX presentation designs.