I guess my overarching point is that Apple is just one company, yet because they own and control the entire ecosystem, people look to them to supply a particular feature or product even if Apple may have zero interest in doing so (be it for time or profit reasons) because no one else can.
For some years now, Macs and iDevices have quite happily used the same wired and wireless networks as everything else, - including all the key Internet protocols - so in the case of WiFi routers, someone else
can and
has done and offers a far greater range and diversity of products than Apple ever could. There's no need for Apple to make WiFi routers. I'd say the same thing about servers, too: not sure why anybody would
want to use MacOS on a server when the only advantage it offers over Linux/BSD is a nice GUI and good desktop Apps... (When XServe first came out it had some USPs like PPC architecture and no per-seat license fee, before Linux had really gained commercial respectability). Ditto external mice/keyboards, printers and even, to an extent, displays (although there probably wouldn't be 5k displays without Apple).
In the case of the iMac (and other Macs), though, only Apple can make a Mac - and Mac OS as an all-purpose OS is in danger if there are strategic holes in the hardware line... For such a huge company - and, what, the #4 manufacturer of personal computers - the current Mac line really is a bit of a fragmented mess that seems to be in constant transition (why are there 2 types of 13" MBP
and a separate MBA range? why has the 16" been updated and not the 13"? why do the iMacs still feature spinning rust? Why build the Mac Mini into a case form-factor originally designed around a CD drive leaving no space for a GPU or decent internal storage? Will the iMac Pro ever see an update, or will its improved design ever trickle down to the iMac?)
...however, I think the current iMac design is probably the least of Apple's problems - yeah, thinner bezels would be nice (but its still the only thing on the market with a 5k display) and a better adjustable stand (but not at $999 a pop, please!) but the main thing I'd change is
make it not an iMac! - I'd like a mid-powered desktop Mac thanks, not a choice between an all-in-one where the screen lives and dies with the computer and a none-in-one Mini with a separate box for the CPU and GPU (with a list of warnings about eGPU compatibility...)