The problem with that in Nintendo's mind is, its not worth it. They would sell more games for sure, but in Nintendo's mind the console becomes obsolete. But their entire business is around consoles and all the third party games they get the money from too. In order to sell their console to as many as possible, they need to have these blockbuster exclusives. In example this is why Microsoft is also going back to exclusives too, and Sony does less again.

Don't get me wrong, I'm not a fan of this. I only play on PC and doing piracy since decades. But from the business standpoint, I understand where they are coming from. Platform holders operate differently than third party devs / publishers.