I bought some AirTags specifically for this reason. The main thing for us is knowing quickly that the bags are in the correct airport. In the past we have been hanging around the luggage collection when a bag was in a different airport, and also when it was with us but was late getting in the belt. Just knowing for sure that it is there is a huge benefit in cases like that. If a bag does end up in the wrong place we will know very quickly so that you can report it missing and get on.
Because of Covid we have only had one opportunity to try them out. We were able to confirm that the bags had arrived with us within 5-10 minutes of landing, and some time before they arrived on the luggage collection. It was very good to get that confirmed.
As a small additional benefit, we also knew when the bags had come out without having to stand in the scrum of people, which made that a nicer experience.
Overall I think they are worth the money. We keep them in a rucksack (or similar) in everyday use. They haven't been needed yet, but it doesn't hurt to have them.