The developer console says that its compulsory to add achievments.
You don’t need to use the Google Play Services Plugin to publish to Play Store. I assume that’s what you’re asking.
Yes but it says you should have at least 5 achievements to publish your game
If you are using google play services then it appears you need to have 5 achievements set up. However, if you are not using google play services plug-in you can still publish to the google play store. The application in my signature I made does not use google play services plugin.