Here is the DARKO Daily-Plus-Minus career progressions for Jeremy, Keldon and Devin. Moreso than looking at these and asking "are these numbers good", I like to focus on the trajectories. This tells us what my eyes generally tell me and what other stats suggest: Keldon and Devin pretty much are who they are at this point, while Jeremy is really taking a leap.
Here is a chart of some well-established stars. You can see guys who are still young (Luka and Shai) are still on the ascent, whereas guys like Giannis and KD (who are still great) have plateaued or are on a downswing. That doesn't mean they aren't great (and Giannis is having one of his best seasons ever), it just says that they are largely fully developed. It's kind of amazing that Luka, Shai and Jokic are still on an upswing.
The DARKO explorer is great, I encourage folks to play around with it. You can find it here:
https://apanalytics.shinyapps.io/DARKO/
Also play around with the "Player Profile" tab. Lots of great stuff there.