It’s the differences in the aspect ratio. You cannot compare screen sizes based on the diagonal alone when the aspect ratios are different. A 6.0" 20:9 screen is smaller than a 5.7" 16:9 screen. And in terms of width, the 6.5" 20:9 screen is also less wide than the 5.7" 16:9 screen, which can matter for certain things (like typing).
Also what’s not helping is the curved screen, I find it takes another few mm off in terms of usable screen area, which makes a screen feel smaller than its stated dimensions.
It’s the differences in the aspect ratio. You cannot compare screen sizes based on the diagonal alone when the aspect ratios are different. A 6.0" 20:9 screen is smaller than a 5.7" 16:9 screen. And in terms of width, the 6.5" 20:9 screen is also less wide than the 5.7" 16:9 screen, which can matter for certain things (like typing).
Also what’s not helping is the curved screen, I find it takes another few mm off in terms of usable screen area, which makes a screen feel smaller than its stated dimensions.