Lenses for the most part should not be put into a “does not work for” category. A 70-300 is fine for video if use correctly, on a tripod and if you need a zoom. There are things that make one lenses better than the other but you have to fit the lens to the need.
With small sensor cameras like the 7D or T2i 35mm would be considered the standard focal length, similar field of view as your eyes (on film and full sensor camera this is 50mm). So anything below that is wide angle, things look push back. Above 35mm are telephoto and things look closer. Not only does the focal length change the field of view, it changes the feeling of the picture. A CU of a face that fills the same area of the viewfinder with a 50mm or a 105mm lens will feel totally different. This is why this is no absolutes with use this for that, it is artist choices, you just need to learn by experience what works for you in a given situation. This is why photography and cinematography is an art form. Everyone can get lucky and capture a beautiful picture every now and then but a professional knows how to create the look he is after.
I sure there are a bunch of stuff online that goes into lenses. If you are new to all this it would be worth our time to do the research.