>> If your goal is to make unique objects that you cannot find anywhere, then, sure, 3d printers are the future
In reality, uniqueness is overrated. Given a really large pool of objects to choose from(which are manufactured in mid quantities) , there's not a lot of consumer need for unique objects.
The largest market consumers do need unique objects is the healthcare market. But the economics there are totally different. for example 3d printing of dental crowns existed for a long time , but it doesn't(yet) captured the market with lower cost solutions(although it certainly has the power to do so, technically).