I had a 2006 A6 with air suspension for 12 years, no issues with the pump, during the 12 years I replaced the rear air springs & front struts with aerosus parts. I would consider this normal wear & tear, considering my friend with a steel sprung Passat replaced the springs & dampers every 2-3 years due to cracks & leaks.
From my experience the air suspension is no less durable than steel springs plus better ride & load levelling.
Had my 2013 Q7 for 2 years now, no signs of any air suspension issues.