Before tablets my family had 4 or 5 MacBooks/Macbook Pros. Now we all have iPad tablets which perform the same functions. Still have a couple Mac Pro desktops for real work.
Good thing you clarified the second sentence with the third. iPads can't replace all the functions of the Macs, and vice versa. I have both. Same with vehicles, I have a truck, a sedan, and a couple sports cars - each is superior in some functions to the others.