For average applications a monitor with sRGB colour space is sufficient. If you are working with photos made by more luxurious digital cameras or image processing for other purposes than online publication, a monitor with a wider gamut is no unnecessary luxury. We tested five models with wqhd-resolution.
While monitor manufacturers like to play with the 'millions of colours' that modern monitors can display, a regular model can only display a fraction of the colours that the human eye can see. This is clear when looking at a CIE-diagram - this rounded triangle shows the range of colours that you can perceive. If you lay an sRGB-triangle over this, you can clearly see that big parts are outside of this triangle.
For the daily use of a computer this is not problematic. By far the most applications are designed to operate within that sRGB-triangle: therefore there is no 'demand' for the display of colours that are outside of the sRGB-triangle. However, in the world of graphic design and industrial design there is a real need for a wider colour range. There is also an increase for digital video processing, now that wider colour spaces are more common there. Within the full hd-standard the Rec.709 colour space was more or less the same as sRGB, with ultra hd as new standard, we also need a considerably wider colour space. This so-called Rec.2020 gamut cannot be displayed completely by any available monitor or television at the time of writing. Because of this, the DCI P3 colour space is often used as in-between, but cameras do usually record in a wider colour space.
Monitors with P3-support are rare. At the moment Apple is calibrating their products for this range as standard, but monitor manufacturers do not. These manufacturers do offer monitors with AdobeRGB, which is wider than P3, but it does not equal Rec.2020. Nevertheless, if you work with images a wider colour space is a step forward compared with sRGB.