Perfect. I also have problems with those courses and tutorials you mentioned and they frustrate me. I planed on writing post on same topic but now I don't have to :D. I will be slamming link to this post in commens of those videos/blogs :D.

The context of code modules matters nails it perfctly.

When I was introduced to SOLID years ago by those same low level courses/tutorials parroting one another I was really confused because creating interface for everything simply doesn't make sense, be pragmatic.

Clap and follow from me, let's promote this.

Thanks for sharing.