Apple has such a critical mass by integrating it into iOS that nothing can compete. The closest equivalent I'm aware of is Tile, but the crowdsourced detection is limited to Tile users, not nearly the entire Android base. If Google were to buy Tile it might be able to compete.

However, Tile doesn't have the anti-stalking provisions of Air Tags--something that's both good and bad. Personally, I feel Apple went too far with the anti-stalking.