It's been a long time since I stopped really following the new camera releases from Nikon, Canon, Sony, etc. It's even longer since I let my skills in building computers atrophy and disappear.
These two facts resemble each other.
As 2020 comes around, my workstation computer is from 2012, and so are both my cameras - a Nikon D3200 and a Nikon D600. I see no reason to upgrade any of them.
These two facts also resemble each other.
In both cases, a technology reached maturity - or at least maturity enough that we were no longer in the zone where technology was moving so fast that each release cycle delivered tangible end-user gains. The computer sector seems to have settled and I don't think Intel is going out of business any time soon, but I'd be amazed if we don't soon see some changes in how cameras are marketed and sold.
In short: the cash-cow layer of ordinary people buying compact or entry-level interchangeable lens cameras (ILCs) is gone - they all started using their amazing cellphone cameras and never looked back; and at the same time the features of ILCs reached a plateau, which removed any motivation for the remaining users to upgrade.
I don't think it's a coincidence that the cameras I have - and which represent the last big leap forward - are from 2012: a bit more than one product cycle after the peak of digital camera sales in 2010: The camera manufacturers would be flush with cash, in a business with amazing year-on-year growth, and set to outdo each other. New models are released, sell well due to being a big leap forward, resulting in the peak of interchangeable lens cameras sales, and... sales nosedive and have been dropping ever since. I bought in at the peak.
Not just because cellphone cameras are getting quite good, and not just because it's much easier to share photos on social media with a cellphone - but also because there just aren't that much more to research and develop in the field of consumer-or-professional grade cameras without scientific breakthroughs, if by "camera" you mean something that looks like a DSLR. (In the market of cameras for space probes, spy satellites, and the like there's enough money to take on that scientific breakthrough.)
Quantum efficiency is up to about 40%, so the best you can hope for is a halving of the noise. Resolution is at 24 Mpix, and while we're now seeing 60 Mpix, that's only a 50% increase in linear resolution. Gimmicks like the sensor shift 240 Mpix resolution of the Sony A7R4 don't work. Not to mention - in order to even keep up with these sensors you need expensive lenses and near ideal shooting conditions.
Barring someone figuring out new laws of optics or lenses of unobtanium and wishalloy, we're up against the laws of nature - and with cameras being "good enough", there's no real motivation to take on that challenge.
At the lower end of the market where we find the average consumer, the interchangeable lens camera is about as relevant as a large format view camera. Does the large format camera give you better photos? Yes, in a technical sense. But with smartphones being much more convenient, easier to use, and producing great photos, the average consumer has no motivation whatsoever to buy and carry around a dedicated device. Nobody except those really interested in getting the particular results that only a dedicated camera can give you will do so.
Which is where I expect the ILC industry to end up - a small market segment for professionals and hobbyists with money to spend, with not much new technology coming out. The sub-$1000 range is probably dead - with razor-thin margins and no large base of consumers to make up for them, nobody is going to bother with it. The $1000 - $2000 range will have some "entry" models, but the market will move to $2000 and up. (Leica will still be around - but there's room for approximately one Leica in the world.)
Some people obviously have a hard time accepting the fact that the current golden age of their hobby has come and gone, but I think it's all part of a natural technology cycle. We just happened to live through it, instead of viewing it as a flood of usurping upstarts who "don't get the art" or as ancient technology that we're only too happy to see recede in the rear view mirror.
Personally, I wonder what I'll think when I look at my D3200 and D600 in ten years. I'm sure I'll always treasure the moments of packing my camera bag and spending a day outdoors before coming back home and seeing what I ended up with this time. I'm also sure I'll pack my bag with something and spending time outdoors - but it'll probably be a proportionally more expensive device with not proportionally much more capabilities, its price being driven up by only having a small enthusiast-and-professional market.
1. Appendix: Others
C.J. Odenbach at 678 Vintage Cameras[a] has written a good three-part series of articles on the topic: The Contraction(s) of the Camera Market - Part 1[b], The Contraction(s) of the Camera Market - Part 2[c] and The Final Contraction of the Camera Market - Part 3[d]
So what incentive is there for people that are most concerned about cost and convenience to look at a dedicated camera (whether compact or interchangeable lens is irrelevant) that costs as much or more as the phone they already have, and is slower, heavier, more cumbersome, requires a 400 - 500 page instruction manual (that you often have to download separately) to understand how to use, and still cannot move your pictures where you want them to go with a few swipes of a finger in a matter of seconds? Zero...zip...nada. (...) The consumer market belongs to smartphones now, and it is never going back to the camera manufacturers.
So where are we headed? Eventually, back to the niche market of the 19th century.
2. Appendix: Digital Camera Sales
Source: CIPA[f]. CIPA did not have numbers for December 2019 as of the time of writing. The sales for December 2018 were substituted. Since the market is in a decline, this most likely overestimates the sales for 2019.
3. Appendix: Camera Capabilities
3.1. Low-Light Capabilities
The low-light capabilities of DSLRs climbed steadily until 2009, and the increase has been quite modest since. Note that the scale is linear - if it had been in stops the curve would look even flatter. This indicates that we're nearing the maximum quantum efficiency.
Resolution - when mesured in megapixels - keeps going up. However, if we look at linear resolution the picture is not one of rapid increase.
Linear resolution has only increased by 40% since 2011's 24 Mpix cameras, and a doubling - which would result in a 96 Mpix full-frame sensor - seems to be out of reach.