Text tables can be overwhelming for users. It's hard to know where to focus your attention!
Where are the highest and lowest values in the data? What patterns are there? Upgrading a text table to a highlight table can often do wonders, but a highlight table doesn't provide a singular focus. It will likely highlight high, and maybe low values too.
That's where a custom highlighter can be so handy. Why not let you user control which values they want to call attention to?