From a multiplicative effect and the current lack of funds it very well could be. Small improvements to development (reduction in bugs, reduction in cpu waste, etc) to things as widely used as these could mean that your $1 donated got multiplied millions of times in dev time saved.

This massive leverage is sort of unique to open source because it’s non-rivalrous. Resources you donate like food, shelter, etc can only help a limited number of people.

Note that this analysis of highest-impact does not make any moral judgements about which is more important. I personally would rather pay to help build plumbing in Uganda rather than this, but it definitely won’t have the same leverage.