There needn't be a lot of difference, if that single trusted party still signs a lot of other CA certificates. You don't just need to trust the root certificat

There needn't be a lot of difference, if that single trusted party still signs a lot of other CA certificates. You don't just need to trust the root certificates intsalled, you need to trust all signed CA certificates those root certificates installed (except for public key pinning, which will ignore installed root certificates).