In a nutshell: the word stealing is a vague umbrella term.

Would you classify making clones/copies out of a thing and sharing them stealing?

Thank God that GOG exists

Steal is like taking away a cupcake from your bakery.

Piracy is like analyzing the cupcake and thus revealing its recipe and I share it to everyone. (You wouldn’t lose your baked cupcakes but everyone makes clones out of them from the recipe.)

Especially Indie games, DRM-free games (GOG) and physical books.

I never bought and never will eBooks

Only physical copies and piracy (so I can actually own my stuff)