Interesting solution that I'm not sure is available/affordable to the general public. An airtag is 25$.
The ideal technology simply does not exist…
Is the current tech. It's deployed and it works. Would a gps/cel enabled device be easier? Yes, but it'll be bigger and require more power too.
Ideally some future tech will not require batteries or they will last a year or so.
Great project, I am happy to see this area pushed forward.