I don't see why?
It is like Macs machines: they get obsolete before they failed
in any way. DSLRs have way less moving parts to go wrong
but the supporting technologies are moving on fast
I have owned 5 digitals and none of them lasted more than a few years. The longest runner was an Olympus E10 bought about 2000 which was still running up to a few months ago when I sold it but even that was having issues - the big one being you would find it hard to find CF cards that it will work with and even less likely to find SmartMedia cards. The original old style SM cards tended to fail even back when they were new so in not much time the camera may be working but how will it write its images without a memory card. You can't ram a modern CF in it because it wont work - the camera was designed to use quite small CF cards which were all there was at the time - it can't address a card thats x10 bigger thats available these days.
As an aside the memorry cards I had for the E10 were worth more than the camera so it wasn't all bad selling it.
Most of my digitals have failed due to shoddy construction, plastic parts falling off and in three cases the electronics just gave up. For a digital there is soooo much to go wrong. The sensors decay over time and the LCDs do too. In fact some late film cameras that had LCDs are already failing and theres no replacements possible. You can machine up a metal component or 3D print a plastic one for an old film camera - you'd find it hard to make an LCD screen or a new IC when it fails.
On top of all of that electronic components deform and decay if not in regular use. Store that DSLR in a cupboard for 30 years and I bet it wont be running when you take it out. A mechanical film camera will be fine. Some of its grease may harden but a bit of exercise will soon have it going again. Electrolytic capacitors are the worst offenders for buggering up - they gradually decay and eventually (if your lucky) fail. If your unlucky they leak and the corrosive fluid inside just dines out on everything else . One of my Nikon expensive compacts did just that. Electrolytics are cheaper than tantalum capacitors and thats why they get used. Plus it probably suits the manufacturers to have the camera fail quite quickly - gets you spending on a replacement.
The manufacturing philosophy for near on everything has fundamentally changed - back the 1960s and 1970 cameras (along with most other things) were an expensive luxury item. So if you were going to part with your cash you wanted some assurance it would last. Manufacturers honoured that unspoken compact and the classic film cameras were built to run for a lifetime of normal use. People were tighter with their purse strings then and wanted reliability because they didn't have money to chuck about buying a new one every few years. For many people it would literally be a lifetime purchase. Today ....who cares about lifetimes, who cares about sustainability - I just want the latest and I want it NOW !! The average Joe will just keep on spending. Even if the camera actually lasted it will be obsolete in no time - 5 megapixel, 10, 20, faster write speeds, better program modes, what about accessories -0 it does you no good to have a working camera if you can't get any support - the lenses are all electronic now as well so another way to get the camera in a junk box, what about media. You might think SD is cool and trendy - people used to think that about 3.5" disks (they did too).
Film never had that- yes there was incremental development in film but it wasn't pressing. It was measured and slow. If you bought a Pentax Spotmatic in 1969 the advances of the Canon AE-1 with auto exposure 10 years later didn't lessen your cameras ability to get a good photo or make you feel you had to have it. Plenty of people made their choice, Minolta SR7 for instance and just stuck with it for the rest of their life.
Most of my film cameras were made around 1970 so they have survived 40 years and still run perfectly in the most part. One of them is 61 years old. never had a service and still runs perfectly. It took every family photograph I have in the hands of my Dad. I can't see most digitals based on my experience making a quarter of that and when they expire you have just some old plastic in your hands. Not something that a camera tech could likely repair, refurbish - just more stuff for landfill.
Whats going on in the digital world today seems to be a re-run of the 1980s. As the market started to decline (and Canon have forecast Armageddon levels of decline in sales) the manufacturers back then started a frantic constant upgrading - auto exposure, program mode, auto focus, motor drive etc to stop the slide and finally kicked all the quality out and started making cameras of spit, glue, plastic and dubious quality. The rot started with the AE-1 and it never really went back. Nikon held out for a few years but in the end they too went plastic and all the quality was slowly wiped out. DSLR was undoubtedly a blessing for the manufacturers (though on hindsight they all seem to have been a bit slow off the mark) as it allowed them a rapid change of pace, a whole new frontier and a whole new group of consumers. But just as with film the market has reached saturation. Where to go now ???
My forecast would be someone is going to ace it with a digital that looks and feels just like a metal film camera and has some kind of longevity built into it. In my dreams I'd like to think one of the big boys will go retro and re-release an all mechanical film body. After all people predicted the end of vinyl - what actually happened was the market shrank but it left behind some excellent niche players who all moved up market. You no longer see the 'entry level' disc spinners but you sure as hell see some beautiful record decks made to a quality that you never saw when the market was booming and Sony, Akai, Pioneer et al were bashing out flashy looking but poorly performing decks.
For me the goal is hybrid - film cameras but a negative scanner - I just love the feel of a film camera - makes me feel like a girl again