You aren't wrong, it's impossible to detect accurately, there are ways but no reliable ones.
Imagine the following case: I have a server using Skript and this addon, at some point, it stops being updated and I want update my server but uh, this addon doesn't work in newer versions. Now, I have to replace lots of lines of code, search for new and maintained addons which will fill my needs once it happens again.
This case happens more often than not sadly,
@Pikachu and me can confirm it after being helping people in this community for a while. With feature-specific addons, if something breaks, you don't have to worry about replacing everything because you were totally dependent in only one addon.