Oh dear, that escalated quickly. I'm only ten days into writing about photo stuff, and now I'm touching the hottest iron in the furnace. I'm not sure if I want to enter the arena where the crowd is already shouting: "gear doesn't matter!" "why gear matters!" "gear matters, but..."... and so on.
First of all, let us appreciate that we are offered a choice when it comes to photography tools. There is a plethora of options from which you can choose, and let's be thankful that there are literally dozens/hundreds of products in any price range.
Be honest: Us human beings are wired to want more, to want something better. And that is what the industry happily offers. And nowadays, it manages to offer us excellent entry gear, that lights the spark for a very interesting hobby, and adeptly exploits our self-improvement drive to want more.
Now this is a tricky thing. We mix up two goals, i.e. getting better and wanting more (stuff). And because it's easy, and we seemingly experienced it already, we think that we are better at something by using better gear. Ultimately, we use that misconception to justify the money we spent. Buying a Leica does not make your photos look like Henri Cartier-Bressons, just as buying a '59 Gibson Les Paul does not make you play and sound like Gary Moore (aside that you probably can't afford one, at least not a real '59). That is a harsh, obvious, and overly didactic statement, but it serves as a motivation to find better reasoning behind gear choices.
That is what I now miss in so many reviews, and so many gear talks, and it bugs me that I haven't asked for it earlier: A reason. A profound answer to the question of why should I? And don't be impressed by what I call "simple wows", i.e. slight improvements only relevant on paper, or fancy features that you'll never use. Turning around the blatant statement I just made: Why should I buy this, when it doesn't make me play like Gary Moore, or shoot like Henri Cartier-Bresson? That again is a bold question, but it helps to sort out simple wows.
I admit it: This is my way of seeking absolution for recent purchases. As I said, we want more, and then we try to find reasons for it. The other way around is way less common in human beings (not just in matters of camera gear actually). That said, wanting more, and finding joy in "better" things is absolutely legitimate (see? Sugarcoating!). It's just that not wanting something that badly anymore once you got it can quickly become a costly and a regular companion in the gear journey, if not counteracted actively. And if you don't, you might find yourself wanting "better" things all the time without even really knowing what "better" is.
Precisely stating beforehand(!) what should improve, and validating that after the purchase significantly helps to be content with the purchase for a much longer period of time. It drastically helps to enjoy things whilst having them, not before having them, and eventually helps to concentrate on what should be the goal of a photographer: and that is to take good photographs.
I suspect that everybody at some point in time falls into the trap of wanting to "save money", and thus buying on a budget too much. Now don't confuse this with the financial limits you have set yourself (or are set by your bank account, that's a different story!). I'm talking just about comparing two things and deciding to go for the cheaper option, despite being able to get the big deal, albeit at greater cost. I learned this the hard way, and it was a particularly cruel lesson, because I felt getting caught at cheating, i.e. cheating myself by thinking there was a shortcut.
Last year, I purchased two lenses, a 50mm f1.5 and a 35mm f1.2. I read reviews, saw lots of images that other people took, and came to the conclusion that I don't need to go for "the premium option" (since everyone said, the cheaper does 95% of what the expensive one does). I got the budget lenses, and shot perhaps 5 images each. I was furious. What should have saved me money, now looked like a bad fake of something better. It turned out that these lenses did not achieve even 40% of what I wanted. Having seen what the big deal was capable of, I now understood what I was going to pay for. Since then, I hate gear reviews because all they say is whether a product does the job for the author. There is no guarantee that it does the job for you.
As time went on, it increasingly occurred to me how much the photos that I saw must have been edited. Holy crap. Also, never underestimate how many deficiencies can be overlooked in a low resolution photo, and that goes up to 1500 pixels in a dimension. My raw files have roughly 6000 pixels in a dimension, and thus the ability to mercilessly dissect flaws of any kind. Editing these images was no fun, looking at them was no fun either. Even if the overall result was okay-ish, all the shortcomings were burned into my brain, like an ugly brand mark. I could not unsee the crappiness in my pictures, and for this time only, I'm not talking about my bad photography skills. I was also aware that, should I upgrade cameras, the flaws will be visible even more. I sold both lenses. They might be perfect for someone else, but not for me.
Perhaps the disappointment was so big because I've seen better, and by that I mean: I've seen myself taking better pictures of the same spot using a different lens. That made it so obvious who the bad guy was.
More importantly, I learned something about my visual perception of the world, and about the way I look at my own photos. I like to explore both of them. I like looking at every single detail around me, and in my photos because I re-remember it from the day I took the picture. As you can see, I am again trying to justify my recent purchases, and I am having a hard time setting myself apart from a pixel-peeper. It really is a fine line to walk on. Yet, I continue to enjoy the photographs that I've taken recently because I can explore them. So far, the whole journey was well worth it.
So the big question I ask myself nowadays is: Do I have concrete benefits from an upgrade or is it an empty wish? If the benefit is worth it for me (and I can afford it), I go for it, and for nothing less, because I know that the money would be spent twice.
If anything, I learned that I enjoyed photography so much, that I invested more into it than originally planned (time, and money-wise). In the end, it is again a highly personal decision of how much you are willing to put into a hobby (again, extrinsic limitations put aside). The most important thing is that you find a way to enjoy your hobby.
Gear is just a tool to get there, and it stops to have that much impact way earlier than you think. It should not get in yur way though. If it does, you should consider a change. Not necessarily an upgrade, but a change. I've done so by stepping down from 42MP sensors to 24MP again. Perhaps more on that later. Finally: Finding joy in practising is what makes people get far further at mastering their craft than anything else. Ask another guitarist about that, and his name is John Petrucci.