The main advantage is evident: a 43 or a 49-inch TV display is a lot less expensive than a monitor of the same size. In fact, few monitors can compare in size to a mid-end TV.
TVs give us more visual space and the same resolution of a high-end monitor, and having 4K on LCD TVs is now mainstream.
They also feature more multimedia options as every, or almost every, one of them is a smart TV nowadays, meaning that they offer an endless amount of different apps that enable us to use it separately from the PC. They usually have a lot of inputs, digital audio output and a speakers system that is usually far ahead of the one offered by typical monitors.