Deprecation of Build Comparison plugin :-(

I’m very sad the Build Comparison plugin will be removed.
I’m a big fan of it, especially when updating the Gradle version of big and complex builds.
It did me very good service in the past.
It would be great if you could at least consider refactoring it out into a separate plugin project instead of completely removing it.

Has there been any alternative for this since?

Yes and no.
If I need it now, I just use a separate host build where the plugin is still present and run the target build with it.
That works fine as long as it stays compatible.