I wonder if "constant upgrading" is a result of not realizing 1. that no ONE lens will do it all, it depends on what you like to shoot and 2. not understanding that it really, really is smarter to put your money into the lens and not the body (if you have to choose between the two) and 3. failing to realize that it isn't the camera. Until you realize that, you will spend and spend, thinking each new piece of gear will be the magic piece of kit that will bring your photography skills to the next level. It won't. Having said that many people are just gear heads and they just like having the newest, the latest, experimenting with different genres, etc. Nothing wrong with that. I really do believe that a solid knowledge of the technical side of photography can compensate for much of what others try to buy.
Maybe you can't afford an expensive camera body that does well in low light and handles high ISO's beautifully. Or a really fast lens that performs better in low light. If you have good shooting technique (how to brace your arms/body etc) and knowledge of the exposure triangle, (or a much less expensive tripod), you can figure out how to the get a decent shot without the fancy gear. If you don't have the artistic side (an eye for composition etc.), all you might get with ANY camera or any technique is a technically nice but artistically poor image, but that's an entirely different discussion.
I suppose everyone has their reasons for "constantly upgrading" their gear, but I'm willing to bet that my hypothesis covers a great deal of those reasons as I've outlined above. Don't worry about what others are doing with their money. Enjoy your hobby or profession because you can make beautiful images with whatever gear you have and with the stuff you have in your creative brain, regardless of what you have in your wallet. s.