In my list of recommended cameras, I included several “all-in-one” lenses. I find that these are convenient and offer a good compromise. However, serious amateurs and professional photographers probably would not use an “all-in-one.” They have a minimum of three lenses: (1) A wide angle, which is roughly 10-22mm, (2) A mid-range zoom, which is roughly 24-105mm, and (3) a long range zoom lens, which is roughly 70mm to 300mm. The problem with having three lenses is that you have three lenses. They are a pain to carry. They take up room (especially when enclosed in a padded case). They will force you to carry a dedicated camera bag. Most of photographs taken after 2005 on this website were all taken with an “all-in-one” lens. If these photographs are good enough for you, you probably do not need additional lenses.
When would you use an additional lens? If you want to take pictures of buildings in Europe (especially the interior of churches), you might want to purchase a wide angle. On the other hand, if you are going on a safari in Africa, you would probably want to buy a long range zoom in addition to your “all-in-one” lens.