Yes, the effeciency rate of solar is what makes it "worth it" or not, and within the last couple of years it has hit a sweet spot where in many to most cases it is "worth" the investment costs. That said, you need to watch out for unscrupulous installers not installing the latest panel tech, or installers who overcharge, etc, and it is preferable to research and utilize all available subsidies you can get your hands on (tax deductions, insurance, local electricity policies, etc).

The tech itself is at the right level now, it's the middle men and bureaucracies or bad rates that are the main problem. Source: family member who has overseen installation and maintenance of many major solar installations.