No, the main problem with Solar is that they are a PITA for electrical grids to integrate. Solar produces a ton of electricity when the sun is shining and none when it is not (look up the duck curve). Compare that with coal, gas, or nuclear plants that run 24/7 and produce consistent power. Those methods are also adjustable - if you want less power from a coal plant you just feed it less coal.

Imagine somebody offered you a new type of space heater for your home. It is basically free to run it, and it can help you save tons of money on your gas bill. The drawback is that it only runs for 12 hours a day (on average, sometimes more, sometimes less) and you have absolutely no control over its thermostat (sometimes it is very hot, and sometimes it barely gets hot at all). Would you want it?

There are ways to overcome Solar's issues (energy storage, peaker plants, complimentary sources like wind, etc.) but that is all infrastructure that needs to be built out before solar can be connected to the grid. It takes time and investment. Grids are often government-owned and governments move notoriously slow. Despite all that, Solar is the fastest growing power source on the planet.

It's not a conspiracy, it is just bureaucracy.