Then there's the cost of disposal. Panels have a lifespan, and when they've lost a great deal of their efficiency the get replaced. Removing the materials from those panels is not easy or cheap as everything is all mashed together. It's like lithium battery recovery, you're always going to lose something when tearing it down.
Some small amount of panels are sold to hobbyists that want to use them for whatever, but when they have 50% of their new efficiency no producer is going to want them.
That being said, the co-op utility back where my folks live have covered their substation right of way areas with panels. That's a perfect use of that space since nothing else can be there.
https://en.wikipedia.org/wiki/Cost_of_electricity_by_source
Economic feasibility is the question here and one he avoids answering. Could be on purpose but I doubt it. I don't think he understands and to be fair, I understand the basics enough to know he is wrong. He presents the recycling batteries and solar panels as a closed loop and that is not how recycling works. Never has and never will.
Absolutely. You can never get out 100% of what goes in, and there are energy costs to getting that little bit out. I'm sure processes will become better with time, but right now it's terribly inefficient.