Whether you consider it magic is up to you, but, unlike a destructor in RAII, there is nothing automatic going on. If you don't explicitly invoke a destructor, you won't get a destructor.
The fact that you can explicitly invoke the destructor to happen later is simply syntactic sugar, just like if/else/while, or any other control construct more powerful than a conditional jump instruction.
> If you don't explicitly invoke a destructor, you won't get a destructor.
When you explicitly invoke a "destructor", you do it on many code paths (and miss one or two)
>The fact that you can explicitly invoke the destructor to happen later
You don't specify where the `defer`-red "destructor" will be invoked.
And more importantly, you can choose what destructor to call. This is perhaps what's most underrated about defer, because defer can select among many different destructors possible, at multiple different levels (group free with arenas, individual free, etc).