I was just testing a panel 45 minutes ago that I purchased in 1999. These are off-grid panels mind you, not grid interconnected with all the regulations and permits those require. Anyway, the ‘99 panel still manages 95% of the output of a similar panel purchased in 2015, which is remarkable and much better than expected. Even if there is some error in measurement the longevity is terrific. So I don’t know where the ten-year replacement comes from unless it is just a stupid obsolescence rule to sell more panels.
I expect to be still using that panel when it is 30 years old.
IMHO, off grid is the only location that makes sense for solar.
The neighbor told me they were 10 yr solar panels and that they would have to be replaced then. I am sure the solar panel companies have made adjustments so they HAVE to be replaced much like the kitchen appliances that used to last decades but only last a few years now.