4K is a nonstarter for me (and I think most people here) because text scaling just looking horrible, there is no cleartype equivalent in MacOS.
Upon re-visiting scaled resolutions in MacOS, I believe issues related to non-integer scaling are over exaggerated. Some people just pass the myth to others without understanding the issues. I'm not denying some YouTubers and users observed significant sluggishness in their applications once after plugging one or more 4K monitors into their Intel Macs. But for others, 4K monitors should be adequate for a lot of users and many use cases.
Text clarity under scaled resolutions is far from 'horrible'. Mystically some people just claim they're seeing blurry text..
For artists requiring pixel-perfect work, scaled resolutions are not for them. For people not fallen into specific combinations of Mac and applications, then you're fine with scaled resolutions. That is if you don't notice perceptible slow down in your daily applications, then you're fine with 4K monitors configured to operate in a non-integer scaled resolution in MacOS.
Having considered all available & limited 5K options (Samsung S90PC included) recently, I'm actually intended to get into 4K monitors instead. LOL. 5K has existed for a decade. It's about time for a break-through in the coming years in both technologies and prices. 4K seems filling the shoes very sweetly for now. But I understand it won't be one size fit all, and some will genuinely need existing 5K or 6K for their work.