No, it’s not. You know exactly what people mean by borrowed power. But I’ll explain it to you anyway.
They are systems, like the legion artifacts, azerite gear, essences and covenants that give you powerful abilities only good for that one expansion. Nothing about them carries over.
Gear is something you will always acquire throughout the game to build upon the power you already have.
Of course there’s a lot more that goes into these systems that you need to do to stay relevant before you can actually play the game and do actual content. But all people like you want to do is argue and say “we’ve always had this”. Stop playing stupid. You know better. You’re only making yourself look bad for no good reason. Just stop.
We will always have talents, gear and our spellbook that blizzard will continue to build upon, we won’t always have the covenants, just like we don’t have the artifact weapons and won’t have the azerite anymore. There’s the difference.