At kaggle platform, winners are required to share solutions. While others share solutions because they want to.

To be eligible for cash prizes, 1st, 2nd, or 3rd on the final leaderboard will release their top solutions under an open source license for ongoing use and learning.

This is from the competition rules it its in the description.

It means we need to wait a little bit. :)

To be eligible for cash prizes, 1st, 2nd, or 3rd on the final leaderboard will release their top solutions under an open-source license for ongoing use and learning, the same was mentioned on https://zindi.africa/competitions/cgiar-eyes-on-the-ground-challenge but the code was never shared. I guess the description page is mostly copy-pasted for every competition