Are the order of importance of camera specifications completely personal according to your own needs?
Could be.
I see it this way: a camera is a tool for doing a job. The job determines your requirements of the tool, which in turn determines which tool you select of those available. The job here is making the kind of photographs you want to make, in given lighting and given conditions.
Key to ease of use with a camera is whether it fits well in your hand (because different people have different size hands) and whether the controls you want access to lie within reach but don't get in the way of holding the thing. This becomes more important the more control you want over the camera (i.e. when using the camera in manual mode).
I know resolution in MP isn't everything it once was. Chip size changes that measure's importance. Max ISO sensitivity? Lens range? F number of lens? Frame speed? What is the importance of it all?
The concepts of film photography still apply. You're still controlling exposure using a combination of shutter speed and aperture to record light (also be it via a sensor rather than on film). A good lens will make a clearer, sharper image, all else being equal. Shutter speed control is important for freezing action. Flash will freeze action if there's not enough light, illuminate your subject in dim light, or pick them out from the background if necessary. Optical image stabilisation will reduce camera shake, in effect allowing you to hold the sensor steady for longer, though it won't freeze the subject.
ISO is the equivalent of film sensitivity (ASA). Except on a digital camera it is settable on a shot by shot basis. A low ISO setting generally gives better sharpness and more dynamic range. High ISO generally comes at the cost of reduced image quality, though the bigger the sensor, the less pronounced this effect. 'High' is relative to the age of the technology. High ISO in 2002 was ISO 400. In 2007 was ISO 1600. Etc. Almost all compact cameras will have AUTO ISO as the default setting, so you'll never need to think about it if you don't want to.
Of course, cameras are consumer goods and so they're made to sell to the market as it currently exists, and so they're subject to fashion. You might consider 4K video capability to be a fashion. Whether you benefit from that capability depends whether you want to shoot video. You might consider a large monitor or touch screen functionality to be another fashion. Does it make a better camera? Manufacturers certainly seem to be making their camera bodies smaller, because their research will be telling them the public wants small, slim products that will fit in a pocket, like their phone does. But a small camera needs a smaller battery, which needs charging more often.
Does this mean a new camera will be better than one from ten years ago? Only in certain respects. Whether they are significant for your photography depends on what you value in a camera.
For a travel camera I'd value these things, in this order. (I'd sacrifice the things at the bottom of the list for the things at the top of the list, to stay within budget.)
1. Long battery life - there is a standard test of this, known as the CIPA standard, useful for comparing cameras
2. Handling and size - something that's not too small for my hand, and has space for my thumb to rest on the back - only truly knowable by handling the camera
3. Low cost of spare batteries
4. Low cost of camera
5. High quality lens (i.e. sharpness)
6. Shutter priority mode - the most important 'manual' mode for the kind of photography I would be doing on holiday
7. Optical viewfinder with dioptre adjuster - optical is useful in bright light and when panning to follow a moving subject; the adjuster because I wear glasses
8. A protected monitor - the twist and tilt monitors are protected when the camera is in a bag, if the screen is folded in against the camera body
9. Fast lens (f2 or as close to this as possible) - faster meaning brighter
10. Usable results at ISO 400 setting - i.e. not too much noise or noise reduction artifacts at ISO settings up to and including 400
11. Built in flash with some kind of evaluative metering system - so the camera can automatically reduce the flash burst when that would make a better photo
12. Control over the JPEG contrast setting (or RAW mode so I can control the contrast when I get to my computer)
13. Zoom range of approx 28mm to 80mm (35mm film photography equivalent) - the zoom could be larger than this but I'd want at least this within range
That spec was being met by many of the 'enthusiast' cameras or 'prosumer' cameras ten years ago, those models dubbed 'enthusiast' cameras or 'prosumer' cameras, featuring larger than average sensors and RAW output. They can now be bought cheaply.
Monitor size doesn't matter to me on a travel camera, as I won't be reviewing the images on the camera much. Video doesn't matter because I don't shoot video. Number of pixels doesn't matter because my images will be viewed on screen, and not printed. Any image above 4MP looks fine on a screen, as long as the camera has a quality lens, etc.
The usual caveats apply to all this, i.e. your requirements may vary. That spec list would be fine
for me, taking photographs mainly in daylight, mainly landscapes and social photography. But those would just be my requirements.
Finally, there's also something to be said for using the camera you've already got, and figuring out how to get the results you want using it. That would (a) show you the limitations of that camera and (b) make you into a better photographer, which would (c) inform your future choice of equipment, and reveal which features you
don't need.
