Because you should not, the interaction is way more advanced than that, actually, as in: it allows you to do more than just attachment:
Find a tut on that one component specifically. It’s only useful if you want physics. Otherwise it may get iffy. And a springarm (or manual vector interpolation) could work better.
Also, this seems a tad strange:
Shouldn’t we be attaching things inside the player character blueprint? Seems like it’s done inside the held item?