Earlier quoted context omitted.
Chromatic adaptation is definitely one of the trickier questions in color management. Here's my take on it. For the most part, when looking at a monitor, chromatic adaptation is pretty good. In other words, RGB #FFFFFF looks white, not light blue, and #808080 looks gray, not bluish-gray. It does start falling apart when you mix different lighting, for example holding a white piece of paper to the screen under normal…
D65 is the sRGB whitepoint mostly because it is the CIE Standard D Series Illuminant, i.e it is a Standard illuminant like A and should be use preferably when typical daylight modeling is required. A display by tuning of the primaries intensity can match a lot of different whitepoint, reaching anything from D50 to D90 is certainly doable.
Illuminant A is a black body radiator that approximates an incandescent light bulb. Illuminants B and C are attempts to approximate daylight by putting a colored liquid filter in front of the black body radiator (or incandescent bulb). Illuminant B is a simulation of tropical noon daylight, while Illuminant C is a simulation of average daylight at a higher latitude (more contribution from the sky, less from direct sunlight).
Illuminant C was widely used in colorimetry, but it didn't match real measured daylight spectra especially closely, so the D illuminants are a replacement based on some physical measurements taken in Rochester (where Kodak was based) and London. Colorimetric applications that previously used illuminant C mostly switched to D65 instead.
(Note that real outdoor daylight spectra vary dramatically depending on place, time, and weather conditions.)
For details, see https://en.wikipedia.org/wiki/Standard_illuminant
> reason D65 is chosen for the sRGB white point is that it is fairly accurate, in other words it's pretty close to the actual white point of the monitor I'm looking at now (Dell P2415Q).
There is also influence the other way. Monitors have a D65 white point to match the spec.