Im curious for more in depth detail about the differences between 1440p at native scale or 4k at 2x scale, does the loss of effective screen space not negate an

Im curious for more in depth detail about the differences between 1440p at native scale or 4k at 2x scale, does the loss of effective screen space not negate any gains in crispness? I've only recently upgraded from two 1080p screens to a single 2560x1440 screen and I'm finding the extra space incredibly useful. That being said I absolutely love the fine text on my retina macbook.