I think by default they should have a large lens which doesn't stick out much by default. Then have the option of attaching those lenses.
One size does not fit all, as we can see with the current 17 lineup - some people don’t care about good camera setup at all and prefer their devices to be as slim and light as possible (Air). At the same time, we have people complaining about how ugly Pro 17 camera modules have become. It’s hard to please Apple customer lot, LOL, and the more model choices we have, the more difficult it gets.