1. In some cases, healthy skepticism will save you money - because not everywhere you can get a good economic effect from using a solar power plant.
2. Many solar power skeptics base their conclusions on theory and outdated technical information.
3. The solar energy market is developing rapidly, just look at how much attention the government pays to it.
4. Should you approach the promises of installers and dealers of solar equipment with distrust, of course - your task is to find decent contractors who will tell you about all the risks and unjustified expectations from the construction of solar stations.
5. Is the payback period of 4-5 years realistic?
It is realistic, and even faster payback periods are possible. It all depends on the initial conditions.
You can get a calculation of the cost and possible generation of your own solar station
https://summerlab.store/products/calculation-of-an-individual-simulation-of-a-solar-station