Panel degradation is very easy and cheap to fix. Our original panels costed about $2,000 each 400W (made sense in our circumstances, recoup in 7 years). After a couple decades we just added 2kW more power for about $300. In another couple of decades you will buy the same for less than $100 probably.

The fun part is that we might never recoup the cost of our gasoline backup generator, as it only worked for about 10 hours in 30 years.

Anyone that worries today about degradation has zero real interest in this stuff, just complains for the sake of complaining.