Why did Greenidge only play 128 ODIs out of a possible 206? Compared to other WI batters like Viv, Haynes etc he skipped a lot of ODIs. I couldn't find any good reason for this and chatbots were making reasons without any sources. Obviously, some of these might have been an injury but that's 78 games!

I couldn't find any good reason for this

How hard did you look?

The first idea that comes to mind is to compare and contrast the ODI careers of Greenidge and Richards which largely overlap, and identify which series or periods Greenidge was out of the team. This is your starting point. A pen and paper will be handy.

Greenidge: https://stats.espncricinfo.com/ci/engine/player/51901.html?class=2;template=results;type=allround;view=match

Richards: https://stats.espncricinfo.com/ci/engine/player/52812.html?class=2;template=results;type=allround;view=match

Coming to a Caribbean site, of all places, and asking other people to do your spadework is a losing propositiion.