Ask HN: It's 2023, what are the best free OSS Slide-Making tools?

Or, It's 2023, we have GPT4, and I would love to not use Powerpoint or Google Slides.

There's got to be something better.

I'm especially looking for the ability to easily create slides with diagrams. I am familiar with text-to-diagram tools like mermaid, d2, etc, so I'm also curious what are the most popular/effective ones.

Also important is the ability to collaborate across diverse types of people, i.e. not necessarily developers.