Many of us are? And we can replace parts from third parties.
It is getting more and more integrated though which makes it hard to replace parts. But that has more to do with greed and size requirements than vertical integration, a soldering iron can amend some of that. Driver situation isn't by any means something new or necessarily an indication of vertical integration either.
Hence why laptops and 2-1 hybrids are basically back to the days of vertical integration of 16 bit computers, whose the PC was the only exception.