Even if they can do better, will it be better than Carplay in 10 years? Or 20? Will I get free GPS map updates for that long?

Some brands don't even do OTA updates, so you'd have to get your car in for a service if there's a new feature or bug fix in an update you care about. I'd never want to do that for a map fix when I could just use Carplay where Google Maps (or whatever else) has already fixed it.

And even if they do OTA updates, they won't be updating those maps in 10 years, much less 20.