I think this disappeared with Retina displays.

I'm still using a 2019 iMac 27" and starting to think about Linux again.

I've got a 2014 Retina iMac and a 2017 Retina iMac. Both of them run flawlessly but are now past Apple's support window. And third party software developers are mostly already adopting a "LOL we don't care" attitude about them. The hardware works impeccably, but software developers refuse to lift a finger to make their software run on them anymore. The Apple ecosystem is infuriating. With great sadness, I retired both of them a few months ago and am now running a boring Linux box with a pretty standard DPI monitor. I miss the Macs but their window of usefulness is way too short.