Most apps can be uninstalled from Pixels / Android One phones these days (including Chrome, YouTube, Google assistant app, Play music/movies) etc. so they did change quite a bit these last years.
Unfortunately OEMs still love to abuse the "Don't allow installation" flag on APKs to prevent you from uninstalling Facebook, LinkedIn, etc. (I'm looking at you Samsung).
I really don't think you can uninstall play services from any phone. They have become slightly better by not installing apps like google+, but that's because they have killed those apps off themselves.
Unfortunately OEMs still love to abuse the "Don't allow installation" flag on APKs to prevent you from uninstalling Facebook, LinkedIn, etc. (I'm looking at you Samsung).