Apple design is the polar opposite of the MX-5. The MX-5 is a masterpiece of mechanical design and function. Apple makes minimalist purely electronic fashion gadgets that are highly form over function and remove user agency.
It’s a terrific car if you want a great handling convertible at a low price point. As you said, it’s fun.
It’s not good at moving a lot of people or things, or going really fast, or lasting for 500k miles, or being as cheap as possible. Other cars are good at some of those things, but what is the Miata missing that is otherwise required to be a ‘good’ car?