While Lightroom and Elements are designed for Photographers. Photoshop opens doors for you to the creative industry.
Digital Photography and Adobe Photoshop today come hand-in-hand. There are no questions about it. When you're getting serious in photography, you will need to get serious about Photoshop. That means you also need a computer that's powerful enough to handle the program in addition to a Wacom tablet. There are other choices, such as Gimp.org and poorly made tablets, but if you plan on getting serious about photography to make a career out of it. Then, you will need to start practicing with Photoshop with a Wacom tablet as these tools are industry gold standard.