Information on how to use Adobe Photoshop, or another other piece of software, is free. Back when I first started teaching in the 90s, software manuals were always included with software. Eventually the paper manuals went away and were replaced with help menus. And anybody who uses any type of software today knows that the best place to get free information is on Google.
But if you are wondering why people would pay money to get something that they could get for free, it's all about synthesis. Sure, the information is out there, lot of it. In fact, that's the problem. A good school, or training company, goes to the trouble of gathering up the information and then re-presenting it in a way that makes sense.
It's all about presentation.