Number of slides don't matter
"Whoa, you have 200 slides?"
"What? You only have 20 slides?"
Both questions are equally worthless.
The quality of the presentation isn't directly proportional to the number of slides. Don't spend time in optimising the number of slides. Instead focus your time on:
1) Sketching the flow of your presentation
Your presentation should only have a single thread and few (only few) branches coming out of it. Spend time on building out this flow, outside your presentation app
2) Sourcing high quality images for your presentation
They might be photos from your phone, screenshots from a YouTube video, quality memes (my favorite) or even a hand drawn comic. Use that as an anchor while you speak
3) Choosing & practicing key moments
Your presentation will have 2 or 3 key moments that the audience will take away. Don't let them decide what that's going to be, you own it. How you set up the slides and practice the narration up to those moments matter. Make it theatrical, but not too much
200 slide presentations aren't boring
20 slide presentations aren't invaluable
As always, exceptions apply.