The same person who buys at $1,799 5K iMac. You're way off on your entire post.
The person who is in for the $1,799 5k INTEL iMac will be shown the 4.6k 24" iMac and the value proposition will be adjusted to show that it's still a good deal. What Apple choose to offer for that money will be up to them.
Apple could create, say, 4 SKUs of a 24" 4.6K iMac and spec it advantageously because it could start with an 8Gb/256Gb/512Gb M1 base spec for a lower pair of SKUs and then upgrade to 16Gb/512Gb/1Tb M1X for an upper pair of SKUs. BTO from the Apple site would up the storage and RAM options
I doubt Apple will start to vary base clock speeds on the chipsets based on what we've seen so far unless their manufacturing starts to produce lower quality CPUs that are stable at lower speeds. So the differentiating points are likely to be amount of compute and graphics cores and the usual ram/storage hence the suggested SKUs as above.
Remember, as you try to fire up your flame throwers, even in the iMac Pro days when you could (with Intel) compare like with like - Apple
never went with what a majority of subscribers would have chosen spec wise. Dual raid PCIe 3.0 4x SSD for fast performance, Workstation class Xeon CPU, ECC RAM, heavy gauge aluminium case, huge PSU, and more slots that you can shake a stick at.
So many hobbyists are busy speccing up their dream Macs with Adata SATA QVO SSD, cheapest possible slowest RAM, steel cases and then claiming Apple should sell it for that cheap. It's tiring. They never ever get what they want and only end up whinging more.
Detailed specs are almost meaningless, because a non-upgradable all-in-one computer has to cater to a wide range of needs.
A "balanced" budget might allocate 20% for RAM+SSD, 20% for GPU, and 20% for monitor. A few months ago, you got 32 GB RAM and 2 TB SSD for under $400, if you didn't have any specific needs. Prices are a bit higher now, but they should go down.
Once the component shortage ends, $400 will buy a 3060 Ti. By raw specs, it's much faster than a 32-core Apple GPU would be, and it's a bit overkill for most non-gamers.
The $400 monitor is currently a 27" 4k one. A 32" 6k iMac would have an obvious advantage here, but the average buyer would not appreciate it that much. Very few people are interested in $1k+ monitors.
Let's start with your last point - a point which is common to many people in speculation threads - the PC builder who wants Apple to build a Mac to their exact specification and budget.
The $400 4k 27" monitor you quote is just what
you want Apple to release because it would fit
your personal budget. Problem is, I can find a lot of low brightness POS 4k TN 250 nit 75% sRGB garbage panels from no name brands, or I could spend 4 figures on an IPS 99-100% DCI-P3 sRGB 1000 nit photo accurate panel with hundreds of local dimming zones (like an ASUS ProART -
link included).
And Apple still won't touch that Asus panel because it's not 218/219ppi.
You don't include too much detail but your $400 monitor budget gives you away. Have Apple released anything for you recently?
At least you understand that a 6k iMac would be a niche thing and that's why I am saying if such a thing was on the cards it's clearly going to replace the iMac Pro and not be some commodity unit that people think they can get for $1700 and put their own RAM and storage in.
You might have missed it, but the 27" retina 5k screen is in a $1k monitor and I reckon it sells well enough in an iMac for Apple to have kept using it. Would you rather Apple use a budget TN panel 23" 1080p screen to make it even more affordable? This is effectively why a detailed budget is important - because Apple will continue to use stuff that some of us don't feel are important in their own dream Apple spec.
$400 for any GPU is moot because Apple won't be using third party GPUs and any extrapolations based on articles that are taking benchmarks for the existing 8 GPU cores in the M1 and multiplying by 4 are similarly moot. The reason is Apple were never interested in getting the highest performance out of AMD or Nvidia. It was always about power efficiency and noise and it's clear that Apple will call it a day when they reach their own internal targets - eg it just has to be 'adequate' for the job at hand without breaking the TDP budget.
You can see now that Apple use GPU acceleration for stuff like video rendering, if it works for gamers then fine. But don't be fooled by Apple's apparent inability to use 'good' graphics. In the last 5 years
Nvidia have spent 1.5-4Bn dollars a year on R&D. Apple could match that and have some expert chip designers and access to TSMC. Basically, Apple could match that and see what they turn out in GPU tech over the next 5 years - but you won't ever see the results of it in a PC because they won't sell separately. I'm ready to sit back and look at benchmarks for the GPU side of Apple's pro business but the more important thing with VR on the horizon is Metal and the software rather than ultimate horsepower on paper. That's a digression though - back to the discussion.
Your 'balanced' budget for a PC, even in the current day and age, is also confusing if you look at the expected bill of materials budget of the iMac. We can guess how much the CPU, RAM, motherboard, and SSD on an intel Mac costs, and a 27" panel to Apple's spec probably dwarfs all of it put together. And the custom machined aluminium case, how much does that cost?
Apple aren't going to be hit as bad during this current component shortage but they will have plans to mitigate - look at how impossible it is to get a PS5 at the moment, even phone shipments could be hit this year.