Millions of lines of code, years of development.....
.....but to be fair most of that work went on creating a snoopware ecosystem.
I never cease to be amazed at just how bad most customer facing software is these days. Software development seems to be stringing together library calls as fast as possible to make your product with no consideration for functionality or resilience -- just get it out and wait for the customer to complain (but don't provide any way for them to do this, of course)(at least one that works). Whether its a graphical application on a phone or tablet or customer service phone line our agility in development invariably results in stuff just not working.