You can have a 27 inch WQHD USB-C monitor with charging and hub for 300-400$.
I hope your livelihood doesn't depend on your psychich abilities.
I have a couple of 25" 1440p (also WQHD) Ultrasharp U2520D Dells with USB-C - they are fine for me. however, you don't specify the model you
use (you only go virtual shopping and mention what you 'can' get so we can't compare). The USB-C charging hub in the Dell would be no use for powering or charging an iMac though.
Apple are making sure they can cater for video/photographic work so they put more budget into their panels. That's their heritage and reputation and also a great marketing point that is always wasted on some people who vocally have a go at the perceived overkill of a 4.5K 24" panel that does 500 nits (commodity screens are commonly 300) and is on the DCI-P3 colour gamut (they've not gone into details on the new 24" tech page at time of writing).
Too many people come out and claim they can buy a 24" panel for $150 without comparing like for like.
The same people will be crying more at how much iPads - especially the 12.9" iPad Pro - cost.
Anyone who doesn't like the quality of panel that Apple choose to use for their iMacs are welcome to buy a Mac mini and add the monitor of their choice. Apple actually did all of them a favour by completely levelling the playing field - everything will be M1 CPU and it's already been pointed out that a Mini plus a cheap monitor of choice will prevent a lot of wasted column inches crying over Apple's component choice not meeting one particular person's taste/budget.
If you don't like it - go to Dell.com and stop filling these forums up with noise.
I think I'm quite satisfied with my
psychic ability. I prefer to call it an eye on Apple's marketing mentality. Check out my posting record if you have the time and see how far back you need to go before you find my first mention of a 24" panel with ARM CPU and a 14" and 16" MacBook - the latter got launched with Intel, the former is still being rumoured. These are NOT done with any secret knowledge or leaks. They just make good marketing sense at the time as a reaction to the butterfly keyboard issues of the time and the forthcoming ARM CPUs and I justify every point.