In broad terms, I can understand why Mario Kart 8 might be hard to justify for some players. It's a re-release of a game Nintendo put out three years ago, and that Nintendo fans (who make up a large portion of the Switch audience) probably already played. That said, this is a fantastic addition to the Switch library, not just as a great game but as one that benefits from the system's core features. It adds the requisite new content and fixes the one large oversight of the original. Mario Kart 8 was already one of the best in the series. Mario Kart 8 Deluxe is even better.
The Disney Afternoon Collection may not have the consistency of Capcom's previous work with the Eclipse Engine, thanks to its library varying in quality. But it is just as reverent and breezy, and the addition of the Rewind feature helps ease the journey into the past. If you were a fan of even a few of these games, you owe it to yourself to see them presented so respectfully for a modern audience.