Obviously if the current best-selling phone was worse then it would not be the best-selling phone. I believe that his point is that without innovating (copying if you will) it probably wouldn't exist as it is today, or if at all, which would be a loss for the consumer.

You could interpret that a few different ways, but I read it as either "the current best selling phone (iPhone?) would be worse (and not necessarily best selling) if Samsung did not copy Apple" or "the best selling phone if Samsung did not copy Apple would be worse than the best selling phone when Samsung did copy Apple."

Yes. Super cars are not best selling cars.