This is an excellent suggestion - worth taking the time to look.
However, the monitor in question does not have HDR enabled, and the internal retina display (Mac Book Pro) does not present the option.
Regardless the behavior is the same; that is to say the insertion point "glow" is too intense and obstructs vision, accuracy of typing. Further Toggling HDR - for me on this monitor - does not reduce the "glow".
I am even seeing the "glow" typing in this text field on Apple Support website... it is a black cursor, gray gradient glow... and while not intense, it is still annoying to me. The glow is still intense enough to be a bother... impedes instant feedback on the typing line particularly with punctuation and diacriticals.
... then of course the insertion point disappears altogether inconsistently. at times, maybe for a few moments, and completely invisible, until you leave the app and come back, or reset on a different page... or a different field on the same page. smh
I'd rather turn off the glow effect all together and use some other mechanism (simple color change) to indicate dictation input or some other listening "state" the cursor / insertion point is trying to communicate.