Yes a lot are going back to timing chains but they still have a life and a recommended change period.
Regards timing belts some cars are worse than others by a long way and will fail if the recommended times or milage are ignored, the Ford Zetec engines will go on for 100,000 miles and eight years or more but some of the breakages are caused by idler wheels and water pumps failing before that, also lots of short runs (heat and cooling cycles) will easily shorten the life.
I remember when some manufacturers started to not have any keyways on bottom pulleys, that must have caused a few "problems" for the DIY brigade
