Yes, that's part of it. It has to speak deep (sometimes elusive) truth. People will be engaged. They will learn. They will use it.
And you can use the slides forever.
Kinda like stand-up comedy. Ever notice that there are 2 kinds of comics, those who riff with the drunks to get the cheap laughs and those who work at an act to speak evergreen truth, getting deep laughs (and even a few tears). We should be like the latter.
I could see that working for presentations for a general audience like a TED talk or maybe intro/closing slides, but otherwise many presentations are context-specific, and trying to frame the content as a "deep truth" might not fly with the audience.
Yes, you are correct that specific situation require specific numbers.
I think the difference is that you can add evergreen content to the specific numbers.
But I guess if it is a daily 15 minute sales meeting for something like the number of sales made yesterday, it isn't going to require anything but numbers.
But maybe once a week or once a month, the sales meeting could address bigger issues. The "why's" and "wherefores" that are evergreen. These types of meetings can keep people engaged at a deeper level, rather than only look at numbers, where people can become disengaged and not motivated as much.
Yes, I agree it’s good to sprinkle them in, but not for every slide, like the OP advises. I think the challenge is that evergreen content, by its nature, is general and can come across as irrelevant to the specific topic at hand (and easily trend towards cliche). The OP describes all other slides as obsolete, but I think that’s okay in many circumstances.
What does this mean? That it sticks to high-level, timeless concepts?