They will eventually stop being beginners.

However beginners or not, unless your primary file format is XCF, GIMP will always annoy you about not saving your image even though you did it - just instead of saving it in its own proprietary format that nothing else supports, you saved it in something that can actually be shared.

Never annoyed me. I was too busy appreciating how good free photo editing software is.

Well, it annoyed others, that doesn't mean they cannot also appreciate how good GIMP is. It isn't like you can either like ALL aspects of a program or NONE with nothing inbetween.

Beginners won't do anything to their images that would necessitate any other format than JPG. Otherwise they wouldn't be beginners. I've now got over a decade experience with Gimp and I still don't need anything other than JPG.

You should try layers; they're really useful.

I can't think of a single use case for layers, to be honest. They only ever annoyed me, because I had to switch layers for editing some things that were automatically their own layer, like text.

Wouldn't it be fun if, like some other image editors, GIMP would merge newly created text into the image and make the text non-editable? :) So much simpler!

I'd prefer that behavior.