React Native on Android: Cannot run program "node": error=2, No such file or directory

The iOS version works fine, but running Android Studio on my Mac I get the following Gradle Build error (paraphrased):

:ReactNative:Running ‘[node, -e, console.log(require(‘react-native/cli’).bin);]’ command failed.- Where:Script ‘/Users/…/Desktop/…/node_modules/@react-native-community/cli-platform-android/native_modules.gradle’ line: 154- What went wrong:A problem occurred evaluating script.> Cannot run program “node”: error=2, No such file or directoryCaused by: java.io.IOException: Cannot run program “node”: error=2, No such file or directory

I've tried so many things:

• Following the React Native development set-up: https://reactnative.dev/docs/environment-setup
• Following this advice about [renaming?] the node path: https://stackoverflow.com/a/54007652
• Following this advice about symlink: https://stackoverflow.com/a/52779097
• Ran brew install node. Message: node 14.2.0 is already installed, it’s just not linked. Tried to run brew link --overwrite node, error /usr/local/share/doc/node is not writable.
• Tried to uninstall and reinstall all the package managers, node, yarn, whatever.

I used to be able to still run yarn android in Terminal, but even that has stopped working.