In that same video he also says that the tools should not modify colours, in order to preserve adjustments made earlier in the pipe.
So while the user shouldn’t worry too much about “accurate” colours (*), the tools should be accurate (in that a change in luminosity should not modify other parameters).
(*: in most cases , you don’t even have the information to go for accurate colours, unless you have a colour target or other known reference shot under the same lighting conditions. Hard to do while birding)