If you are setting up the ANDROID_HOME environment on MacOS Catalina , .bash_profile is no longer apple's default shell and it won't persist your path variables. Use .zprofile instead and follow the environment setup instructions in react-native documentation or others. .bash_profile will keep creating new file which won't make the path permanent or persist on closing the terminal on your system path.
Modified as it's providing answer to the frustration of setting up android_home environment on MacOS.