Photo of an iMac with nothing whatsoever plugged in...
vs.
Photo of a Mac Studio with - apart from the necessary power and single USB-C monitor -
five USB-C/USB-A devices
and an HDMI display connected?
Seriously? Surprised you couldn't find a photo of the Studio with a wired network plugged in for good measure. /s
Now find a picture of an iMac with half a dozen additional cables connected and hanging down in plain sight (rather than tucked behind the Studio) - for bonus points, imagine one mounted on a display arm, or even a decent adjustable stand (hope you ordered the VESA option when you bought the iMac - no swapsies!) with all those cables dangling.
Also, enjoy fumbling around behind that 27" panel whenever you have to plug or unplug something (even an SD card!) - much easier with the Studio, even discunting the front-mounted ports. (Yes, I own both a 27" iMac and a Studio so I know).
Sure, the iMac is a "sweet spot" for people who really never plug in more than the power cable - but the 27" iMac was also the only viable option for people who wanted a more powerful desktop Mac and
did need to connect it to everything but the kitchen sink. If Apple could produce a large-screen iMac
alongside a decent Mac Mni/Mac Studio line then I wouldn't complain - but history has seen Apple's desktop range consisting of an underpowered Mac Mini, an eye-wateringly expensive Mac Pro and the iMac for everybody else.
...if you take "footprint" literally. But it doesn't actually take that much more "real" desk space because it usually parks under the "overhang" of the monitor. Or, it can located on a shelf, under the desk (along with peripherals and everything but the display cable) or simply shoved out-of-the-way where it isn't taking up
useful working space.
If that's the dealbreaker, white replacement thunderbolt 4 and IEC power cables are widely available.
Soft rags are widely available and can be conveniently upcycled from old clothes etc. You don't need to pay $20 for an Apple cleaning cloth, let alone $2000 for a new, non-dusty computer.
In terms of
internal dust accumulating - well, an iMac has exactly the same problem and is significantly
harder to open up for cleaning than a Mac Studio or Mini (see Apple's repair guides online). Not saying it's easy, but it's a "having the right screwdrivers" job, whereas doing
anything to an iMac involves cutting through the glue holding the screen on & obtaining replacement adhesive strips.
Not as smooth hardware integration, including webcam
The Studio Display you show has internal webcam, sound system and microphones, all via the one Thunderbolt cable. Many third-party USB-C displays offer similar. I've got a Logitech webcam plugged into my USB-C
display's USB hub and it Just Works.
Meanwhile, anybody doing any sort of AV production work (not uncommon for a higher-end Mac) will - whether they have an iMac or a Studio - probably need an external audio interface and monitor speakers (and a higher quality video camera if they're YouTubing etc.)
anyway making the integrated iMac stuff redundant.
in 4-5 years your monitor gets old, dusty, likely malfunctioning and obsolete as well as your CPU, so I would not keep the monitor for decade.
YMMV but every display I've ever bought has served more than one "generation" of computer. Esp. since the switch to LED illumination (those old CF backlights did lose their mojo after a while).
The 5k screen in my 2017 iMac is
still as good as anything available today (the Studio Display is maybe a tad brighter) and I'd be using it with my Studio if I could. The 2017
processor is slower and noisier than my Studio, and stopped getting new MacOS versions in 2023. Even the cheapo 4k display I bought in 2016 is still being used as a display for a 2020 MBA. I used an Apple LED Cinema display at work for 8 covering at least 2 Macs and was disappointed that I couldn't quite get away with swiping it when I left.
For my next Mac I was considering a Mac Mini plus Studio Display because it would exactly match what I have now in terms of screen real estate and physical desk space needed, but the cost will be almost double what I paid for my 27" iMac.
Don't expect any hypothetical new large-screen iMac to be significantly cheaper than a Mini + Studio Display combo.
A second option is a Mini with a pair of third party displays. I'd get more screen real estate, but would have to accept lower pixel density and poorer colour reproduction.
Don't rule out a 27" 4k screen until you've tried one. "Looks like 2560x1440" mode (misleadingly named, since it's actually 5220x2880 downsampled to 3840x2160 which shows far more detail than 2560x1440) will give you essentially the same "real estate" as a 5k iMac with a
slight softening of detail. I used a 4k 28" screen alongside my 5k iMac for years and although there
was a difference in sharpness it was still pretty good.
Unfortunately, there are a couple of articles out there on the tubes which make it sound like using 4k on a Mac will make your eyes bleed - along with super-enlarged images/simulations of worst-case examples of scaling artefacts - which would only really affect people trying to do pixel-accurate editing
without using zoom (in which case it takes seconds to switch to a 1:1 or 2:1 mode to get the job done). If you go hunting for artefacts and let yourself get triggered by them you'll find them, but I've found them insignificant in general use. A 30" or larger 4k display will probably be useable in 1:1 mode without scaling (your eyesight may vary).
Colour reproduction should only be an issue if you cheap out on a low-end third party display. As for desk space, you could look into monitor arms or dual-display VESA mounts.
It's true that 5120x2880 @ 27" is the sweet spot for MacOS, but unfortunately the days of $1800 iMacs with 5k displays is over (it's amazing that Apple kept them going for so long once 5k failed to take off on PC and bring down prices).