I have that dream too.Still waiting for my dream machine - iMac Pro 32"/6K (& hopefully with ProMotion and FaceID)
But seeing how well MacBooks Air and Pro have repeatedly sold for the last 3-4 years, I see Apple putting all its efforts towards those long before doing anything new with iMac.
It's not impossible that we'll get a big change for iMac.
But considering which Macs outsell the other models by far(!), it's far more likely that Apple would make big changes and upgrades to MacBooks Pro and/or Air.
I see a new, cheaper desktop display and big upgrades coming to MacBooks before any of the other Macs see any big changes.
Apple wants us to buy Mac Studio or MacBooks Pro + Studio Displays and not Pro iMacs, it seems. If it wasn't so then we'd have gotten a big iMac much sooner.