I wouldn't deem it wasteful. Monitors have evolved a lot slower than computer parts generally and using a monitor for a relatively long period is quite common w

I wouldn't deem it wasteful. Monitors have evolved a lot slower than computer parts generally and using a monitor for a relatively long period is quite common with desktop PC users. A midrange 1920x1200 display bought 10 or 12 years ago is quite similar in specs compared to today's low end displays. A few years old 4K and 5K iMacs have high end integrated displays even from today's point of view, but their CPUs and especially GPUs are outdated for quite a few serious use cases. I think it would make a lot of sense to use one as a display for a new workstation setup. But obviously my described use case is a "second chance" for an iMac having served as a standalone computer until its EOL.