It depends on each screen. There are TVs with less input lag than some monitors out there.
You want to use PC/Game mode, and tinker a bunch with the settings of the image, and as Forbin points (I actually bough my monitor based on a review on that site), use a TV that is actually good in that use case.
The "600 Hz 8K 3D holo-vision" marketing stuff goes away as soon as PC mode is engagded, so you really only care about its performance on this very mode, you can mostly ignore any other part of the review as you won't be using that (TV speakers, for instance, should also be not used).
I'm using a TV as my main display, and a monitor as secondary. The day I was deciding this, I cloned the displays and did not notice the mouse pointer lagging behind the monitor (IPS 60 hz). So no remorse on this regard.
TV has worse colours for sure, but pixel quality is the same (I can't say this about some cheap TVs I hooked when my previous monitor died).