I used a panel made in 1975, in 2012, and it still put out it's rated wattage. A 37 year old panel. Why would anyone replace working panels that still have so much life left in them?
Inverter and batteries had long since been swapped out. I was about the fifth person to use the panel. I was staying with some original back-to-the-landers who had purchased the panel along with several others around the time it was made. They swore by Outback Power for their inverters, though I own and like an awful lot of Victron equipment now.
Dark blue encompasses most mass produced commercial panels. Notice there's no change since 2008, and even a modern panel is only a few percent more efficient than the one I used from 1975.
