Availability.
There's already a comment that says something similarThere's already a comment that says something similar, but I also answered a similar question about NuGet (.NET's package manager) a few months ago:
Should we include Nuget PACKAGE folder in version control?Should we include Nuget PACKAGE folder in version control?
I'm not a Java guy and I don't know Maven, but to me it sounds like it's similar to NuGet: a central package repository where dependencies are pulled from during build when they don't exist on the local machine.
The problem is not just that Maven might shut down completely in 10 years.
Even if they "only" have a short outage right now, every project that depends on the repository wouldn't build during that time.
That's why we are saving our dependencies inside the repositories at work.
Plus, with internal repositories (like we have at work), there's also the problem that our internet connection could die (we already had that, and it involved an excavator).
I'm writing software for internal use, and even without an internet connection, we were able to build and deploy.
The last paragraph is probably not as big of a concern with IntelliJ, though...because the repository itself is on GitHub.
