... just seem to be programmed to want the greatest of everything, even if it's far beyond anything that would ever be useful to them. Resolution, detail and all of that in photography seem to be one of those things. Sure, a huge format offer a technically higher level of performance, but the question is whether it will be useful for the kind of photography that you do.
This counts for me as well. I consider myself a beginner so I ask questions to learn. Point is, probably for many beginners, I have a limited budget. But for that budget I want to buy the best possible gear. Since I am a beginner it is hard to decide what the best possible gear is for my situation. What I want to prevent is that I am buying something quite expensive, to find out that what I have purchased lacks in image quality. That is why I think newbies like me are focusing on IQ. I do understand I cannot buy the best of the best. I do not have thousands of dollars to spend on a body and a lens. However, the money that I can spend, I want to spend in the best way possible. Then there are other factors that influence my choice. Like for example, I do not want my kit to be very heavy (because then I won't take it with me) and I also want some decent zoom. So all of this together does not make it an easy choice, especially for a beginner.
Well... far be it for me to tell one what they need, but I would say that with photography, bigger really doesn't necessarily mean better in terms of formats. Sure, a FF format camera, all things being equal will have better IQ than something of a smaller format, but that ignores just how good the IQ of smaller formats can be and the fact that in most scenarios it will be tough, if not impossible to tell the difference in IQ from one format to the other.
What then you're left with then is what you'd want to carry and what you're willing to pay for it. Admittedly, full frame cameras these days can be very compact, but then lenses aren't and so as a full package deal, particularly with a long zoom that you're considering might be a disincentive to carry around and as is so often said on these pages, the best camera is one that you have with you.
I would suggest at least considering an m43 kit as for not too much, you can put together a nice kit, particularly if you go used and you likely would be quite satisfied with the IQ. Faced with the same decision as you, I chose this format and now on my 3rd body and a number of lenses later, I'm still happy with it. Close to 10 years ago I got my first of these cameras, but it wasn't until I looked at the photo sharing site Flickr and looked up m43 to see if the image quality of these little cameras stacked up... and to my eyes they certainly did. 10 years later the tech is even better so that the IQ is far better as well.
Thanks for your advice! I appreciate it. Would you recommend M4/3 over APS-C? When I visit a camera webshop, I only see Olympus and Panasonic M4/3 cameras. Are these the only manufacturers? I don't like the idea of buying a used body or lens. I'd rather buy new, because I'm too afraid to buy something that does not function correctly. Which new camera could you advise me for M4/3? Does not have to be the cheapest, but I probably can't afford the most expensive either. What would be a good 'in the middle' model?
APS-C is fine as well, though in my personal opinion, the only manufactured currently who's really behind the format is Fuji. Canon, Nikon and Sony may have some cameras of this format, but they offer less lenses and see to view it more as something that is meant as a kind of stepping stone to folks trading up to full frame. Fuji has a large ecosystem of bodies and lens, not to mention lots of 3rd party options for lenses as well (and some of those are going to be the real bargains). If I had a few grand burning a hole in my pocket, I just might get a used Fuji xt-5 and a few lenses to go with it. That being said though, the tiny buy still mighty m43 does everything that I need it to.
I currently own an Olympus Pen F body, which I like, but honestly probably wasn't the best choice for someone like me. It's well built, ergonomically nice, but offers more for folks who shoot JPEGs straight out of the camera than for folks like me that shoot RAW and process the photos themselves. My previous camera was an Olympus EM10, which has an older style, slightly lower mpx sensor (16 rather than 20 mpx), but was still plenty capable and something that I used to shoot many of my favorite images with. particularly with an accessory grip (cheap and a very nice addition to the thing) it felt great in the hand and had all of the features that I could ask for. It might have been considered a more entry level offering, but in truth it's a really capable and cheap camera. From waht I've seen, I like the mkII version of that camera even better and I;ve seen those things go for really cheap too. I was just browsing my local Craigslist and found one with the kit zoom even for $150. I'd recommend something like that maybe, though an older Fuji model would also be cheap, though with bulkier, more expensive lens options. Some of the older Fujis don't have the in body lens stabilization (often listed as IBIS), which stabilizes the camera at low shutter speeds so that you don't really need a tripod unless you're shooting at super low shutter speeds. This sort of thing is on most of the m43 bodies and has been super-useful to me. I feel that it kind of closes the gap some between m43 and larger formats as it allows you to get more exposure and that in turn allows for better IQ.
If you're interested in video, you might want to look at Panasonic cameras as well, as in the m43 ecosystem, it's Panasonic that tend to be more featured for that. Models with great video specs are going to be more though as are models that have weather sealing, if you plan to be shooting in a lot of dodgy conditions. I plan to trade my camera up to an Olympus EM 1 mkII at some point as that camera has everything that I want including weather sealing that my Pen F doesn't have, but is going to be far more expensive than the EM10 mkII that I mentioned and in truth the image quality, though great, isn't going to be night and day better with the more expensive body. IQ is surprisingly good with this little format and even with the older style 16 mpx sensor. it might be all that you need.
One thing to try is to look on Flickr for photos taken with any camera that you're considering. You can filter the photos by the camera taken with and in doing so get a sense of waht various cameras are capable of.
Obviously if you go back far enough you will see more differences. I was never suggesting that there were no advances since the start of digital just that things from a purely IQ perspective in recent years have shown minimal advances. 
