I guess I am fully missing your point because I don't see how wishing for an extra spell slot or a bonus extra attack is a wish "in real life" and not "in the game"? Like...them asking for a mechanical bonus to their character isn't a real life wish...and it falls within the general things Wish does. Permanent resistance to a damage type is a mechanical thing, but its listed as a thing wish can do within the spell itself.
I would absolutely grant you that Wish because when the heck are you gonna see someone roll an actual d30. Might even let you use it for an entire encounter.