Re: I bought Sims 4 on Steam on Macbook. Can I link my game to Origin?

@cookiethewook  While you could link your accounts, you still would need to play through Steam rather than only through Origin.  Since Steam doesn't support the Mac version of Sims 4, that's not a viable approach.

In your position, I'd refund the Steam version and wait for an Origin sale.  The Digital Deluxe version of Sims 4 can be as low as $6.25 or so (U.S. dollars) during the frequent sales.