Soldato
the display manufacturers are limited by the panels available in the market, not to mention bandwidth limitations of providing 3440 x 1440 @ 120/144Hz.
There aren't any IPS-type panels with high refresh rate other than the 27" 2560 x 1440 panel used in models like the ACer XB270HU and Asus MG279Q. There's a new 35" AU Optronics AMVA panel which is 2560 x 1080 @ 144Hz but getting 3440 x 1440 @ 144Hz is another question! especially from IPS panels. LG.Display dont even have any current 144Hz IPS panels in their lineup, and they're the only ones with 34" widescreen IPS-type panels at the moment
This has been one of the reasons I've not really made the jump from my 60hx 1440p panel to something quicker. While I need IPS for my photography I'd also like to try the higher refresh rates but don't want to loose the colour reproduction. However, I've never had an issue with 60-85hz and can't justify moving from a 27" to another 27" for minimal gain.