The same can be said about animation. If you look at it that way then portrait artists who paint photo realistic paintings are just wasting their time when they can just take a picture. It all comes down to what you value.
Comics are sequential art, they tell a story through each page, although one illustration can also tell a story it is not sequential. You can combine all your illustrations together and it's not a comic because it's not sequential. It would be completely random at every page turn and you would not call it a comic you would call it a portfolio.
Comics ARE illustrations combined together but they must be sequential otherwise it becomes an art portfolio not a comic.
You can say comics are not special but there are films and animations created from comics. There are professionals who work on creating comics RenieDraws is one of them. So according to my hypothesis I disagree with that quote. 