Is a GPS collar worth it over a basic AirTag holder?

Reviewers across r/FiDogCollar, r/dogs and r/tractivegps generally agree that true GPS collars with cellular service (Fi, Tractive) offer live tracking, virtual fences and escape alerts that AirTags cannot, because AirTags rely on nearby iPhones. The trade-off is an ongoing subscription, and r/puppy101 commenters flag Fi's recent plan changes as a meaningful downside.