It's really not that difficult to understand. Especially for someone whom, IMO, on the forum tries to project the persona of a financial brain trust, knower of markets, crypto expert, etc. I would also guess that your short, terse replies are more trolling than really not getting it. I'd wager you've got time on your hands and are looking for a fun back and forth argument or just trying to bait people. Which is cool, everyone likes to stir the pot from time to time... myself include. Let's just assume I'm wrong about all that.
I'd also bet you already had your mind made up about solar possibly, you didn't even listen to somebody's "spiel" (but I'll take you at your word on that). BTW, a guy on the internet like me or a person whose neighbor has panels and the owner explained it to your neighbor and your neighbor explained to you doesn't count.
It's no more difficult to grasp than refinancing your house. In the simple house example it's going to cost you $3,000 to refinance and it's going to take you x-months of savings to recoup that $3,000. If I plan to stay in the house more than x months I really have no financial choice but to refinance. I might have other emotional reasons not to but, the numbers say refinance. Conversely if I plan on selling before I break even there's no reason to pay money just to have a smaller house payment because in the long run it will cost me more. I think even a middle school kid could grasp that.
There are never any absolutes but with a little homework I think you can make some reasonably safe assumptions to start the cocktail napkin calculations. First and foremost the cost of electricity is probably (not absolutely) going to stay the same or go up. I can't really think of many things we consume on a regular basis that don't go up. For the sake of argument let's take the best case it stays the same.
The system costs you roughly 20 grand. How much are you going to save every month/year? Will that annual or monthly savings be more than the time you plan to stay in the current house? If the answer to that last question is no there's no reason to worry about any other esoteric what if scenarios. You should not consider it.
If on the surface it looks like the time spent with the solar panels would save you money in the long run, it's time to dig a Little deeper. Can you pay for it all up front or do you have to finance it or do you have to sell your $100 KHorns for $11K horns to help pay for some of the 20K? If you're financing it, the time you spend in the house and or the monthly savings have to be greater. Could you take the 20K for panels and do something else with it that makes you more $$$ than your electricity over that same period costs? Could you do something with that 20K that makes you more happy like a world-class vacation and a lifetime of memories? Where are they going to be located on my house and if I find them ugly will I regret it every time I drive down my street? If utilizing the money in a different manner than solar panels makes you happier screw the panels and do what you want.
Things like roof replacement, panel disposal and future buyers turning up their nose are all red herrings. Those issues are already been addressed long ago and are baked into the price of a high quality system. In my experience, these arguments are typically thrown out by people who already have a bias towards solar panels or have spent zero time talking to a high quality solar installation company. You need to get actual references from installations they've done years prior and talk to the homeowners to find out both their experience with the company and the expected versus realized gains. The technology changes quickly and the panels only get more efficient so if you compare numbers today to somebody from 5 years ago you can only do better.
So what's not to get?