While I'm not the person the question was directed to, the 1Ds had the first major-manufacturer full-frame sensor (and this was before the current crop of APS-C ultrawide lenses - you could get to 16mm pretty easily on full-frame, but the widest APS-C lens was also around 16mm, so you were limited to a ~24mm field of view). It also had by far the highest resolution of any major-manufacturer DSLR at the time(the hedging is due to the weird Kodak DSLR (14n, SLR-N and SLR-C) line that used low-quality consumer bodies, but a FF sensor that actually out-resolved the 1Ds). According to the reviews, it was real pain to shoot, but capable of very good image quality for the time if you stayed within their narrow parameters (which pretty much meant staying at base ISO with shutter speeds under a second). The restrictions for decent image quality were unlike the 1Ds, which was heavy, but otherwise a very flexible camera that produced images several years ahead of its time...
What's happened now is that all reasonable interchangeable lens digital cameras (again, for the sake of completeness, this doesn't apply to Pentax Q cameras with tiny sensors, nor to some of the odd cameras we've seen with "Polaroid" or "Kodak" nameplates that have nothing to do with those companies, and maybe not to the Nikon 1) produce images so good, and are so flexible that they are perfectly usable way outside the use cases they were meant for...
The Nikon Z7 is really a landscape camera - and it's a great one... It's pretty much 4x5" level low-ISO IQ in a tiny package that'll take most any weather, with some sharp lenses that fit nicely in a backpack. Think of it as a 4x5" field camera that happens to get a few hundred shots in its film holder. Who'd ever shoot sports with a 4x5"? Very few people since Oskar Barnack first stuffed movie film into a metal cylinder - and certainly nobody outside of a few iconoclasts looking for a very different image since the first Nikon F with a motor drive. Yet a Z7 will do a credible job as a sports camera - there are much better tools, but if all you've got is a Z7 or two, an FTZ adapter and a couple of long lenses, you could go right into the camera pit at Fenway Park and shoot the game (while wishing you hadn't forgotten the D5 at home - it tracks focus a lot better). The most inappropriate possible current camera to shoot a sporting event will still do a better job than any film camera ever could, and better than any digital camera more than five years old.
Conversely, Micro 4/3 is the worst possible currently manufactured choice for high-detail landscape. It gives up resolution and dynamic range to any larger sensor - in return for speed you don't need for landscape. If you're standing on a mountain with nothing but an E-M1 mkII (really a dedicated sports/action camera) and a decent lens, use it! You probably got there with that gear because you were shooting skiers, for which the fast, rugged Olympus is a perfect choice, but want to grab a few scenes as well... Yes, it's the modern-day equivalent of shooting landscape with a motor-driven Nikon F3 with 800 speed film (about as likely a choice as sports with a wooden field camera), but it does a much better job than that... Again, the most inappropriate possible choice today is better than any 35mm film, and as good as any possible digital camera until late 2008 (a very expensive D3x could solidly beat the much newer Olympus at high-detail landscape).
Not only can two specialized cameras do a credible job at each other's specialties, but the broad range of ~24 MP generalist cameras will do a great job at most photographic tasks. Whether you have a Canon 6D mk II, 5D mkIV or EOS-R, a Sony a7 mkII or mkIII, a Nikon D610, D750 or Z6, a Fuji X-T2, X-T, X-Pro-2 or X-H1, or (for the iconoclast) a Pentax KP, you have a camera that does just about everything darned well. Navigate slightly sparse APS-C lens lines and you can add Nikon's D7x00 and D500, Canon's 77D, 80D and even the high end of the EOS-M line, and Sony's A6x00 line to the list. Dealing with both sparse lenses and limited controls, the inexpensive Sony A5100, Canon Rebel (anything from the past bunch of years) and Nikon D3x00/D5x00 lines also produce excellent images.
