You mean it's built in now. It still has objectively existed for a long time now.
There has been an app called AirGuard around for a long time. Also not every Android has play services. There's a large degoogled operating system community now.
With the official Apple app, you had to know that it existed, find it in the Google Play Store, install it, and then manually run it every single time you wanted to check for trackers.
With AirGuard, you had to know that an unofficial implementation existed, find it, install it, and then either run a manual sweep or have it permanently run in the background if you wanted to get notified of trackers near you.
Neither implementation would tell you how long a tracker had been following you, or where it first started following you. Neither option would allow you to ring the tracker. Neither option would allow you to read the information on the tracker via NFC.
So no, this has not "objectively existed for a long time now."
What you mean is that other, far more limited options have existed for a while now.