The camera I use for nearly all my paid work is now two generations old. It has no internal stabilisation, a codec that everyone agrees is limiting, and autofocus that is fine rather than good.
Every year I look at replacing it and every year I cannot construct an argument that survives contact with what I actually shoot.
What the upgrade would actually get me
Let me be fair about this, because I am not arguing that new cameras are not better.
Better autofocus, particularly for tracking a moving subject. This is genuinely improved and if I shot more run-and-gun documentary work I would feel it.
Internal stabilisation, which would let me shoot handheld in situations where I currently use a gimbal or a monopod.
A better codec, which matters if you are grading heavily or pulling keys.
Higher frame rates at higher resolutions, which I use perhaps twice a year.
These are real advantages. The question is what they are worth against what I shoot, which is mostly interviews, mostly on sticks, mostly with controlled lighting, mostly delivered without aggressive grading.
The gear that would improve my work is not the camera
Every time I run through this honestly, the limiting factor in my work is somewhere else.
Lighting, mostly. The difference between a competently lit interview and a beautifully lit one is enormous and visible to anybody. The difference between two camera generations on a well-lit interview is visible to people who own cameras.
Sound after that. I upgraded my recorder and microphones two years ago and it improved the delivered work more than any camera change would have.
Lenses after that. Glass outlasts bodies, holds value, and changes the look considerably more than the sensor behind it.
And then, some distance down, the camera body.
The stabilisation argument in particular
Internal stabilisation is the feature I most often hear cited, and it is genuinely useful. It is also the one where the workaround is cheapest.
A monopod costs very little and produces steadier footage than internal stabilisation does for static or slow-moving shots. A shoulder rig, similarly. Both require you to think about the shot before making it, which is not a bad discipline.
Where internal stabilisation genuinely wins is spontaneous handheld work where there was no time to set up. If that is what you shoot, the argument is strong. If it is not, you are buying a solution to a problem you can also solve with a stick.
The codec question is real and situational
I will concede this one properly. The eight-bit codec on my camera falls apart if you push it hard in a grade. Skies band. Skin tones go strange if you shift them much.
The way I have dealt with it is to expose carefully and set the look in camera rather than fixing it later. Get the white balance right on set. Get exposure right rather than protecting highlights and lifting later. Light for the look you want.
This is more work at the shoot and less latitude afterwards, and it is how everyone worked for decades. It also produces better habits, because a camera that punishes sloppy exposure teaches you not to be sloppy.
If I were doing heavy compositing or aggressive stylised grading, I would need a better codec and there would be no argument. I am not.
The client conversation
The thing I was most worried about was clients asking what I shoot on and being unimpressed.
In three years, two clients have asked. Neither knew enough about the answer to have an opinion about it. What they asked about far more often was turnaround time, whether I could work with their existing footage, and whether I had shot anything similar before.
There is a category of work where the camera is specified in the brief, usually because of a broadcaster's technical requirements. That work is not available to me on this body and I know it. It is a small fraction of what I do and renting for those jobs costs less than owning a camera I would use occasionally.
What would actually make me replace it
Genuine failure. It has taken a lot of use and it will eventually stop working.
A shift in the kind of work I do — if I moved toward documentary or event work where autofocus and stabilisation carry real weight.
Or a delivery requirement I cannot meet, which so far has not happened.
What will not make me replace it is a new model being announced, or reading that the sensor in it is now considered dated, or the vague sense that everyone else has moved on.
The wider point
The upgrade cycle in this field is driven by an industry that needs to sell things and by an audience that enjoys reading about them. Neither is dishonest exactly. Both produce a background pressure that is unrelated to whether your work would improve.
The useful question is not whether a new camera is better. It obviously is. The question is whether the thing limiting your work is the camera, and for most people making most things, it is not.