This (along with my need for multiple displays and a hatred of non-matching bezels) is why I never buy iMacs for myself. It's so frustrating that the Mac mini is so underpowered these days. They used to be great machines (options for quad core, discrete gpus) but now they are clearly entry level only.
I am using 5x Dell (IPS business range) displays that are 10 years old on my Mac Pro that is 8 years old. In that time, I have clients who have gone through 3 24/27-inch iMacs each. It really is pretty wasteful to have to pitch the screen if you need a faster CPU or GPU. I have upgraded both on my Mac Pro multiple times.
Or alternatively, when another part in the iMac dies, the perfectly functional display is thrown out. In the case of 27-inch iMacs, this is usually when the GPU dies. Had a client recently dispose of 3x 27-inch quad core i7 iMacs as the GPUs had failed in all of them! Apple wanted around $1k to replace the video card, making it not economical to repair. It's crazy how quickly we throw away hardware because of the 'all in one' desktop design. I get that the all in one is nice from a 'neatness' perspective, but it's so environmentally irresponsible. Makes more sense on a laptop than a desktop for it to be 'integrated'. Bring on the new Mac Pro I say!
Whoops. Didn't meant to turn this thread into another 'repairability and upgradability' rant!