Meanwhile a relatives system failed before 2 and is now a pile of panels leaning on the side of their house. No way these things are actually lasting 20 years. Or if they are, it's by dint of enough repair & maint to destroy the math even more.
What does seem to be true though is that it's getting better/closer. As the panels get both more efficient and cheaper, it becomes less of a waste of motion.
Like anything else you can buy quality components and install them correctly or you can buy poor quality components and install them poorly. If a solar system fails after 2 years there were defects in materials or worksmanship. A solar setup is a pretty robust thing when done right.
It doesn't take more than a couple trees in the wrong place to make you a lousy candidate for solar.