I dont even think 240 is the sweet spot. With the constantly badly optimised releases or high demanding AAA titles, you will not get 240 unless you turn the gfx down massively. Monitors are pushing the limits on refresh, but we are still in the 144hz era for actual attained FPS. And for those with HDR, many screens wont support HDR @ even 175hz.
Its like the TV world where we now get 8k Screens, but almost zero interest from broadcasters/content creators to make true use of it, with the exception of public displays and advertising.