I imagine you could get something like this for much cheaper that runs on open source software and isn’t limited to one company’s phones.

And doesn't notify you if they are being used to stalk you like the AirTag does.

in addition to what you said i feel like there’s probably better versions of this that aren’t apple

Unfortunately, not really. The competing products in this category are either useless once you're out of bluetooth range (Tile) or are GPS devices with a ton of problems (extremely short battery life, mandatory data plan subscriptions, large size) and none of it runs on or interfaces with open source software.