I’m really surprised this took 3 years after AirTags. Especially since AirTags have been rumored to launch for a very long time before that, and it was a surprise to people that they seemed to be done and just not available (IIRC).
That still leaves 2 years past Apple’s long rumored debut.
Presumably Google would have, eventually, said "ok, enough is enough, we're releasing on X date whether or not you've updated yet". And maybe that's indeed what happened! At that point Apple really would want to finish that update, since not doing so could be a privacy hole for their customers. (The same privacy hole Android users had to deal with in the early days of AirTags when we couldn't detect them.)