Can't a SLR camera make the lens and the body together?

This kind of camera, which combines SLR body and SLR lens, has been around for a long time, and is often called telephoto machine. For example, Fuji HS series, Panasonic GH telephoto series and Samsung NX single battery series are basically designed in this way.

SLR (single lens reflex) is called SLR because it can replace a variety of single lenses with different uses and functions! On this basis, the advantage of changing the lens is not comparable to that of the card machine. Take ordinary photos, you can use a card machine that doesn't need to change lenses for a lifetime; But for professional SLR cameras, it is impossible not to change the lens. You say the card machine is "good", but it is not a little worse than the "excellent" professional photos. Card machine will never produce SLR effect.

Learning photography will help you when you have time.