A gh extension to aim to be a replacement of hub compare.
$ gh extension install kyanny/gh-browse-compare
$ gh browse-compare v1.0.0..main
$ gh browse-compare v1.0.0...main
You may want to add an alias.
$ gh alias set compare 'browse-compare'
This extension is an experimental implementation, so that it does not validate the command line argument and error handling is rough.
I created this extension rather than directly contributing to cli/cli to close cli/cli#4433 because I need to comply with this guidance. If I get a positive feedback, I am happy to submit a pull request to cli/cli.