Life as we know it would be unrecognizable without plants. They provide virtually all our food, directly or indirectly, they produce oxygen and filter out environmental toxins, they are the source of numerous medicines, and they even make our daily living environment more attractive to look at.
There's no doubt that studying plant life in a scientific manner is an important occupation. A number of botanists go on to earn their doctorates and devote their careers to research and teaching, but many find employment working directly with plants.
A degree will give you a broad understanding of how plants function at every level, from molecular processes to large-scale ecologies. As such, you'll be prepared for several different types of careers. In general, though, students need to have a practical, scientific mindset, a hands-on attitude, and a willingness to wait months or years for tangible results.