u/TimeRemovein r/dotnet • Recommends
On “ELI5 Dependency Injections and Constructors”
This free Microsoft video does a good job of explaining why you'd want to use DI using an example:
link to this video
And while it is using Autofac (rather than .Net Core's built in DI) and there's an annoying part in the middle where you're stuck looking at their backs, it is worth a watching to get a good idea of when DI would be useful.