Using TV as a monitor

I have been thinking about buying a larger monitor when my wife suggested using our new large screen 4K TV as a monitor instead. I had tried doing this with our older large screen (HD) TV, but stopped when I saw how poor the color rendition was. I hooked the 4K TV up using a spare HDMI cable and was surprised to see how good it looked as a monitor, but do not want to have an extra HDMI cable snaking along the floor to the TV. My first thought was to use Apple TV to connect my Mini (High Sierra, i7, 16GB RAM, 256GB ssd) to the 4K TV, but I do not know if the wireless connection would be fast enough to show "real time" activity.

I do not play games on my Mac. Instead I use it for photo editing, browsing and some occasional coding using Xcode (to create apps to use on my own system, not professional). Is Apple TV fast enough to keep up with those tasks? Or is there sufficient lag to annoy people using it?

Also, is there any other way to connect my Mini to the TV? I am sure I can get an Apple TV device and use it for streaming, but I currently use a Roku for that and do not need another device only for streaming from Amazon, Netflix and the like. I do not even think that some of my streaming channels are available on Apple TV (for example, Brit Box).

Any help would be appreciated.