1) know AirTags exist (many obviously don't)
2) go out of their way to install Apple's Android AirTag scanner app (only 100k-500k worldwide have done so according to Google Play stats)
3) manually open the scanner app and scan, since it doesn't scan passively in the background; and even then, it won't help you find the speaker-less AirTag, since it doesn't tell you proximity & direction.
I continue to think Apple should have never released AirTags to the public, and should discontinue it. It's a very limited income stream, with limited use cases, and significantly increases the average person's risk of stalking.
Practically all positive social media coverage of AirTags involves someone tracking a stolen stolen items (car, bike). Those use cases are dead, since thieves with iPhones will get alerts, and most thieves with Android will know to scan for AirTags. And since most lost items turn into stolen items after a few hours, that removes most use cases involving losing objects in public.
That leaves "finding your keys within your home" as the only truly "officially supported" use case. Is that worth all the problems, and brand damage?
People will argue that stalkers could always buy trackers, but Apple increased their availability, ease-of-acquisition and ease-of-use by orders of magnitude. AirTags are cheaper than competing GPS trackers, most of which require subscriptions.
I remember seeing a chills-down-your-spine Apple Watch Series 7 TV ad, that featured beautiful remote nature landscapes, with the audio of 911 calls made from people's Apple Watches whose lives were saved by their Watch. Probably one of Apple's best and most impactful ad in the past decade. Compare that to AirTag's impact on Apple's brand. Why did Apple even bother?