What is the average life expectancy of a DAC?

As others have said, no moving parts just electronic components. I have had  a Meridian Direct (Director) for years. Its moved from my main system to my shop system. I’ve dropped it numerous times and it gets full of sawdust, still has wonderful sound. 

My JVC QL-Y55F turntable is 40 years old and still performs as new. And you’re all questioning if you can get 5 years out of a dac? 
Thank goodness for turntables. 

I bought my Ayre QB9 in 2007 based on hearing it at the dealer. Ayre has offered two upgrades since and the sound of each were worth it. So I have a current Ayre DAC but originally bought in 2007. I would research and try to find a company that will either accept trade in’s or upgrades.
Jaytor, the Levinson DAC has always been considered a leader in sound. Many who heard the Levinson in the early 2000’s would still swear today that it’s the best sounding DAC they’ve ever heard. DAC chips are a great thing but implementing them and designing something overall is what matters. I’d also add that I don’t really think that price point is a good determiner. 

My JVC QL-Y55F turntable is 40 years old and still performs as new.

Is your cartridge 40 years old?