A remarkably common theme on internet forums, and probably almost as much in the days before them, is this notion of outgrowing a camera. You might buy an entry level camera, and then outgrow it, and need to upgrade to a new camera.
This is a wonderful idea for camera companies, of course. It's also a wonderful idea for many amateur photographers, the ones who like cameras more than they like photographs.
The implication of the term is that as your skills grow, your camera will begin to hold you back. This can actually happen with some devices and systems. When racing sailboats at some point it may make sense to acquire a faster boat. Generally speaking a slightly slower boat isn't going to be the limiting factor, your terrible steering and bad tactics are why you're losing races. If you work at it, though, you will find that you're doing everything right and still losing the races by a couple of seconds to the other fellow who is also doing everything right and who has a slightly faster boat. A golf club, I imagine, might hold you back. After your swing becomes perfect the inaccuracy of the club is the limiting factor in placing the ball onto the green.
These things simply don't happen with cameras. Well, there are probably some weird corner cases where you could make an argument, but as a general thing your skills do not expand to the point that the camera is limiting you.
What happens is that your taste and desires become refined and more precise, and you learn what manner of photographs you would like to take. Then, in some cases, you will find that a different camera is what's necessary to make those photographs. If your desire is to shoot sports, you may really need a higher burst frame rate. If you want to shoot wildlife, you will want longer lenses (and longer, and longer, without end). If you want to shoot in low light, you may truly need a better sensor.
There are reasons to upgrade. "Outgrowing" a camera isn't really one of them. Perhaps this is the best word we have available to describe the refined tastes and desires, but it still doesn't fit.
If you want to upgrade because, hey, shiny new toy, that is ok. It's disingenuous to assert that you've outgrown the old one.